Donald Trump would be mistaken to think he can radically change the electoral map, Rothenberg argues. (Photo by Ralph Freso/Getty Images)

Donald Trump has boldly declared that he will change the nation’s electoral map.

But as the general election begins, he faces a steep, almost impossible climb to the 270 electoral votes needed to win the White House.

Trump needs to carry all 24 states that Mitt Romney won, with their 206 electoral votes, plus another 64 electoral votes. Based on past performance, state demographics and Trump’s early positioning in national polls, this will not be easy. Even the best-case scenario for Trump looks very uphill.

[Trump fires top aide in urgent bid to retool campaign]

Unless the presidential contest becomes a blowout and puts Indiana, Missouri, Arizona and even more reliably Republican states into play (which is a real possibility), only one Romney state, North Carolina (15 electoral votes), is sure to be at risk for Trump. Romney carried the Tar Heel state by just over two points, but the state went for Barack Obama in 2008, so it could easily flip back into the Democratic column in November.

The most obvious way for the Republican nominee to get the additional electoral votes he needs is to carry the four states (with 69 electoral votes) that Obama won most narrowly in 2012: Florida (29), Ohio (18), Virginia (13) and Colorado (9).

That won’t be easy, especially considering Trump’s problems with Latino and upscale voters.

Presumptive Republican nominee Donald Trump fired embattled campaign manager Corey Lewandowski on June 20. The Fix's Chris Cillizza breaks down what comes next. (The Washington Post)

According to a 2013 Pew Research Center report, Florida and Colorado both ranked in the top seven states in Hispanic share of total population in 2011. Virginia has become less conservative and less Republican over the decades because of the growth of the state’s Washington, D.C. suburbs.

If Trump fails to carry any of those states, he would need to win the electoral votes of one or more of the next- closest 2012 states: Pennsylvania (20), Iowa (6), New Hampshire (4), Nevada (6) and Wisconsin (10). Together, those five states have just 46 electoral votes – less than Florida, Virginia and Colorado combined.

Trump and his allies argue that his appeal among populist voters will help carry Pennsylvania and Wisconsin, and possibly even Michigan (16) and New Jersey (14), radically changing the political map and giving him a number of potential routes to victory.

That seems unlikely. President Obama’s margin in each of the four states was significantly greater than his overall national margin in 2012. He won nationally by 3.9 points but his margin was 5.4 points in Pennsylvania and 6.9 points in Wisconsin.

Republican strategists begin almost every presidential election talking about snatching Pennsylvania and Wisconsin from the Democratic column, and each time they have failed.

The last Republican to carry Wisconsin was Ronald Reagan in the landslide of 1984, when he carried 49 states.  George H.W. Bush is the last Republican to carry Pennsylvania, Michigan and New Jersey, all in 1988, when he carried 40 states in an almost 8-point win over Michael Dukakis.

The idea that New Jersey – or New York and California, which Trump has said he’ll put into play – will be a battlefield in the fall is nothing short of delusional. The mere fact that Trump and his strategists are talking about winning any of those three states undermines the credibility of their overall argument.

During the last successful GOP presidential bid in 2004, Bush won nationally by 2.6 points but lost New Jersey by 6.7 points, California by 9.9 points and New York by 18.3 points. None of those states is fundamentally competitive, and Trump’s bluster does not change that.

Given their recent successes, Democrats clearly begin with an Electoral College advantage in 2016. The party’s nominees have carried 18 states and the District of Columbia in each of the past six presidential contests.

Assuming that she holds those 242 electoral votes, Clinton will need a mere 28 electoral votes from 8 competitive or Democratic-leaning states to win in November.

Republican presidential candidate Donald Trump's campaign raised just $3.1 million in May, while Democratic rival Hillary Clinton brought in $27 million. Here's a breakdown of the two campaigns' finances. (Jenny Starrs/The Washington Post)

For years, some analysts have warned that it is a mistake to believe there is a Democratic electoral vote advantage, noting that each election is different and states can and do move from one partisan column to another depending on the overall election result.

About a year ago, FiveThirtyEight’s Nate Silver noted that in 1992 “you’d have been reading a lot about Republicans’ supposed ‘lock’ on the Electoral College.” Just four years later, that Republican “lock” was undone by Bill Clinton.

Silver was correct that talk of a Republican “lock” overstated the Republican advantage in the 1990s. But not everyone back then thought an unbreakable lock existed.

My March/April 1988 Public Opinion piece, “A New Look at the Lock: How Republicans Can Lose,” argued that talk of the GOP “lock,” which probably dated back to Horace Busby, a long-time ally of Lyndon Johnson and an astute political observer, “misreads history and places far too much emphasis on the 1980 and 1984 election results.”

“The problem with the lock theory,” I wrote, “is that it boils presidential elections down to an ‘everything being equal’ argument – as long as personalities don’t matter, the economy is not a factor, incumbency is discounted, ethics are not an issue, and all Republicans are united behind their nominee. In fact, few presidential elections since 1952 have occurred in that environment, and magnifying a small Republican inherent advantage into a lock draws the wrong lessons from history.”

The fact that each election is different doesn’t change the fact that the map generally favors the Democratic nominee and that the current contours of the 2016 race – including Trump’s problems among Latino voters, more highly educated voters and even white women — poses special problems for the presumptive GOP nominee.

Given where Trump starts in national polls and the combination of states that he must flip to reach 270 electoral votes, the presumptive Republican nominee needs a fundamental shift in the political landscape to have even a fighting chance against Clinton.

That is a very tall order.

Stuart Rothenberg writes about the politics of the presidential and congressional races.