Paul released a statement immediately after President Trump nominated Kavanaugh, pledging to review his record and keep an “open mind.”

Paul would face enormous pressure to vote to confirm Kavanaugh if the vote in the Senate is close. Republicans have just a 50-49 majority given Sen. John McCain’s (R-Ariz.) long absence, but they are hopeful of winning over several centrist Democrats.

The Kentucky libertarian is a champion of the Fourth Amendment, which has established the constitutional right to privacy, and thinks Kavanaugh has a weak record on that issue, according to GOP sources.

Colleagues say Paul is concerned about two rulings Kavanaugh made as a judge on the D.C. Circuit Court of Appeals that favored broad government power to track its citizens.