This newspaper has a long history of supporting U.S. Sen. Marco Rubio’s electoral campaigns, going back to his days as a promising political newcomer from West Miami with a strong measure of personal magnetism and a crowd-pleasing message that served him well as he climbed the political ladder. When he ran an insurgent campaign for the Senate against a sitting Republican governor in 2010, we backed him because we believed, “He has the potential to be the kind of statesman Floridians can be proud to call a native son.”

On occasion, Sen. Rubio lived up to that early promise, never more so than during his freshman year in the U.S. Senate when he led an effort to forge a historic compromise on immigration. It ultimately failed, but the young senator displayed political courage and a willingness to defy his own party. This year, he again broke from the Republican majority by supporting President Obama’s request for $2 billion in emergency funding to fight Zika.

But in many other ways, Sen. Rubio has been a disappointment.

He has fought Obamacare at every step, even though it has brought immeasurable relief to millions who previously had no healthcare. He has joined the Senate majority in the scandalous move to block any consideration of the president’s nominee for a Supreme Court vacancy. He has unilaterally blocked other meritorious presidential nominations for purely political reasons, including confirmation of a judge he himself had once recommended.

Beyond the political differences, there are issues of sincerity and character for voters to consider. First, he reneged on his unequivocal pledge not to run for re-election for a position he once openly disdained — but only after he lost his bid for the Republican presidential nomination to his nemesis, Donald Trump. Then he endorsed Mr. Trump, whom he called a con man during the campaign. And still at this late date, he continues to stand by that endorsement, even as the Republican candidate stumbles from gaffe to insult to outrage.

Mr. Trump’s candidacy is a test of character, and Sen. Rubio is failing that test. How can voters believe he’s sincere when he says he does not share Mr. Trump’s awful views on Mexicans, immigrants, Muslims, women, etc., yet — at the same time — stands by his endorsement of the New York billionaire? His act is unconvincing. It reeks of political convenience rather than political conviction.

And he has refused to issue a clear, unequivocal statement on whether he will finish out his term if he wins reelection. And though he used the June massacre at Pulse, the gay nightclub in Orlando, as his excuse for getting in the race, he has a disastrous record as far as LGBT issues are concerned, opposing marriage equality and adoption by gay parents, and voting against giving LGBT Americans workplace protections.

Democratic U.S. Rep. Patrick Murphy, the main challenger, is in many ways an untested figure. His claim to fame is that he knocked off firebrand conservative Allen West in a Treasure Coast district in 2012. As a relatively new Democrat in a Republican-controlled House, he has had little chance to show what he can do as a legislator.

Opponents claim Rep. Murphy padded his résumé, especially regarding his work on cleaning up the Gulf of Mexico oil spill and his status as a CPA, but a thorough investigation by PolitiFact suggests the attacks are overkill. A more nuanced — and accurate — view is that he embellished his record but mostly did what he claimed.

What is clear, however, is that Rep. Murphy will fight for the right issues, as he stated in his debate with Sen. Rubio on Monday. He supports the diplomatic opening to Cuba, reasonable gun-control measures, the Affordable Care Act, measures to rein in climate change and Roe v. Wade — as well as comprehensive immigration reform and filling the Supreme Court vacancy.

For the U.S. Senate, the Miami Herald recommends PATRICK MURPHY.

U.S. House District 23

In the August primary, U.S. Rep. Debbie Wasserman Schultz overcame both the first credible competitor in her political career and legitimate anger from supporters of Bernie Sanders when emails leaked from the Democratic National Committee, which Ms. Wasserman Schultz, 50, led, showed a bias toward boosting Hillary Clinton’s candidacy.

She now faces Republican Joe Kaufman. He sought, unsuccessfully, to unseat her in 2014.

After all her years in the House, she remains the best candidate to represent this reliably Democratic district. She is, overall, in tune with its needs. Her support for Israel is unwavering; so is her support for the Affordable Care Act, though she wisely recognizes that it’s not perfect. She stands against Republicans’ efforts to privatize Social Security; for her, “Climate change is real.”

And she has a record of accomplishment: She has brought home funds for critical transportation projects; and worked to reauthorize the Export-Import Bank, especially because it has helped businesses in her district expand abroad.

And she is the only Florida Democrat on the Appropriations Committee. She holds a powerful position on a powerful board.

Mr. Kaufman, 46 and who says he is a counter-terrorism expert, sits much farther to the right politically. Where the incumbent was “disappointed” by the U.S. Supreme Court’s rejection of President Obama’s executive order barring the deportation of undocumented parents, Mr. Kaufman said it was the right ruling, and that “the parents should be held accountable for the crimes that they committed.” He doesn’t like the Affordable Care Act and says that he has “no idea whether humans play a role in climate change.” Still he would supports investing in renewable fuels.

Given her experience, the Herald recommends DEBBIE WASSERMAN SCHULTZ in Congressional District 23.

U.S. House District 25

Once upon a time, Republican Rep. Mario Diaz-Balart was better known because of his older brother, Lincoln, who had preceded him in Congress.

But as he concludes his seventh term — and now seeks reelection in a newly redrawn District 25 — Rep. Diaz-Balart has hit his stride. He now is a veteran congressman, fighting for Miami-Dade on issues besides Cuba.

Rep. Diaz-Balart, 55, is a senior member of the Appropriations Committee and is chairman of the Subcommittee on Transportation, Housing and Urban Development. Those seats have muscle.

He admits he’s not one to pass bills. Rather, he says he makes an impact by working the appropriations angle — and successfully. He brings home the bacon. Rep. Diaz-Balart has fingerprints on issues critical to his district: Yes, Cuba-related issues, but also Everglades restoration, Zika eradication, affordable-housing initiatives and Miami homelessness.

He is being challenged by Democrat Alina Valdes, 61, a physician at the Miami Rescue Mission and a political newcomer. Ms. Valdes, a Cuban exile, might be a novice but she is an impressive, knowledgeable candidate and has a future in politics.

She says Rep. Diaz-Balart is going through the motions and is an ineffective member of Congress. A change is needed, she says. The two differ greatly on U.S. Cuba policy. Ms. Valdes favors the current thawed relations; Rep. Diaz-Balart says the Obama administration has done all the giving, getting nothing in return in terms of freedoms for the Cuban people in return from the Castro regime.

The incumbent remains a man of influence in Congress, especially for South Florida. Therefore, the Miami Herald recommends MARIO DIAZ-BALART in Congressional District 25.

U.S. House District 26

This district, which spans a huge area from Westchester to Key West, is one of the relative few in the country where the electorate is considered varied enough to keep the result from being pre-determined strictly by party affiliation. It pits former incumbent Democrat Joe Garcia, 53, against the man who beat him in 2014, Republican Carlos Curbelo, 36.

Mr. Garcia is a feisty advocate for Democratic causes who has been known to characterize right-wing members of Congress as “the Taliban” and who has been involved in public issues most of his life. A former executive director of the Cuban American National Foundation, he once described himself as a “bishop in the church of the (Cuban trade) embargo” who eventually came around to the idea that the embargo needs to be eliminated to promote change in Cuba.

He is a reliable vote for Democratic issues and supports gay marriage, the Affordable Care Act, abortion rights, comprehensive immigration reform, infrastructure spending and action to stop climate change. He favors free trade, but told the Editorial Board “the country is not ready” to support President Obama’s trade deal with Pacific countries.

Mr. Garcia is on shaky ground, however, when it comes to ethics and corruption. One well-reported instance by this newspaper was in his losing 2010 bid for Congress when his campaign manager was later convicted of a misdemeanor for illegally funding the campaign of a phony rival. In the 2012 campaign, the same individual on Mr. Garcia’s payroll pleaded guilty in an illegal absentee ballot scheme. Mr. Garcia himself was never implicated of wrongdoing, but it tarnishes his reputation and should give voters pause.

Incumbent Carlos Curbelo is the kind of Republican all too rare in Congress these days. He’s often willing, in the words of a Herald story, to take a “lonely stance” against his own party when he thinks it’s wrong.

He believes, for example, that, “We need to do everything we reasonably can to reduce the number of abortions,” but he has voted against some of his party’s more extreme measures. He has formed a bipartisan caucus to tackle climate change. He has formed a committee that gives money to Republicans who favor immigration reform, as he does (although it has also been accused of giving money to reform opponents). And he gets high marks for his support of LGBT rights. “He’s such a bold voice for us,” a spokesperson for a GOP gay-rights super PAC told the Herald.

Although he sides with critics of the Affordable Care Act, he’s not ready to toss it until “a worthy replacement can be developed.” In the meantime, improvements to the existing law need to be made, he says.

On Cuba-related issues, he has tried to reform the Cuban Adjustment Act in order to reserve benefits exclusively for those who are genuine political refugees. But he believes that, in light of normalization, the Obama administration has been “overly patient, overly generous and overly forgiving” toward the Castro government.

On balance, Rep. Curbelo is a reasonable voice in Congress who has served his first term well, works in a bipartisan way and manages to avoid scandal. He deserves reelection.

The Herald recommends CARLOS CURBELO in Congressional District 26.

U.S. House District 27

Republican Rep. Ileana Ros-Lehtinen is the dean of Miami-Dade’s congressional delegation. She was the first Cuban American elected to Congress and has served in the House since 1989.

This year, Rep. Ros-Lehtinen is being challenged by Scott Fuhrman, a political newcomer and third-generation fruit-juice bottler. Viewed as promising fresh blood, Mr. Fuhrman has the national Democrats’ backing in his efforts to unseat Rep. Ros-Lehtinen.

Mr. Fuhrman, 34, does not have a clean criminal record — once an automatic disqualifying smear to running for public office. He has wisely, and publicly, confronted four arrests, for which his campaign provides documentation. The most serious took place in 2009 in Colorado. Mr. Fuhrman, then 27, was charged with driving under the influence and prohibited use of a weapon. He was pulled over for improperly changing lanes and admitted to having two drinks. Police found a loaded handgun on the driver’s side door. Mr. Fuhrman pleaded guilty, paid a fine and performed community service.

His local legal problems are highlighted in television ads and fliers from the Ros-Lehtinen camp. The father of teenager Helen Witty, killed by a drunk teen, speaks out against Mr. Fuhrman.

In his ads, Mr. Fuhrman criticizes Rep. Ros-Lehtinen’s well-known opposition to the Castro regime — once her bread-and-butter issue. But through the years, Rep. Ros-Lehtinen has expanded her base, especially in the LGBT community — one of her children is transgender — and is a strong voice for Israel, local environmental reforms, education issues and securing federal Zika-fighting funds. And she delivers stellar constituent service.

The Herald recommends ILEANA ROS-LEHTINEN in Congressional District 27.