Kentucky Sen. Rand Paul is not waiting for the official confirmation process as the former presidential hopeful seeks to stop John Bolton from becoming the next secretary of state.

“Bolton is a longtime member of the failed Washington elite that Trump vowed to oppose, hell-bent on repeating virtually every foreign policy mistake the U.S. has made in the last 15 years — particularly those Trump promised to avoid as president,” Paul wrote in Rare.us on Tuesday, where one of Paul’s former aides serves as politics editor.

Story Continued Below

Former New York Mayor Rudy Giuliani is the “narrow favorite” to be secretary of state, however, POLITICO reported Tuesday.

Bolton, who served in the George W. Bush administration as ambassador to the United Nations, is a leading Republican hawk and an avowed opponent of the U.S.-led nuclear deal with Iran. And Paul, a libertarian-leaning skeptic of the Iraq war, represents the opposite pole of GOP foreign policy.

Paul filibustered now CIA Director John Brennan for nearly 13 hours in 2013 until he could extract a promise from the Obama administration on domestic drone use. He then placed a hold on James Comey's nomination as FBI director months later over similar concerns.

But it will be difficult for Paul or any other single senator to unilaterally block any of Trump's cabinet appointments. After Democrats nuked the filibuster in 2013, save for a few exceptions like Supreme Court nominees, Senate rules only require 51 votes to break a filibuster and confirm such nominations.

After criticizing him during the Republican primary, Paul went on to praise Trump for questioning the Iraq war -- though the New York billionaire has never produced evidence that he opposed it.

As he was weighing a presidential campaign of his own last year, Bolton told the Washington Examiner that he stands by his support for ousting Iraqi dictator Saddam Hussein.

“I still think the decision to overthrow Saddam was correct," Bolton said. "I think decisions made after that decision were wrong, although I think the worst decision made after that was the 2011 decision to withdraw U.S. and coalition forces."