U.S. President Donald Trump assailed opposition Democrats Monday as "obstructionists" who appear set to vote against CIA director Mike Pompeo as Trump's pick to become secretary of state.Pompeo's nomination faces significant opposition on the Senate Foreign Relations Committee, where Republicans hold an 11-10 majority over Democrats. A vote is set for later in the day. But all 10 Democrats and Republican Sen. Rand Paul have announced they oppose making Pompeo the country's top diplomat.In a rare rebuke to a U.S. president on a confirmation vote for a key national security position, the panel could give Pompeo an unfavorable recommendation and still send his nomination to the full Senate. The Senate vote on his nomination also is expected to be close, with as yet only two Democrats, Senators Heidi Heitkamp and Joe Manchin, announcing their support for Pompeo's confirmation."Hard to believe Obstructionists May vote against Mike Pompeo for Secretary of State," Trump said on Twitter. "The Dems will not approve hundreds of good people, including the Ambassador to Germany. They are maxing out the time on approval process for all, never happened before. Need more Republicans!" The Senate panel vote, however, could have been locked up for Pompeo were it not for the opposition of Paul, who said he will vote against Pompeo because he supported the 2003 American invasion of Iraq that eventually toppled Iraqi dictator Saddam Hussein.Several days ago, Trump said, "I will say this about Rand Paul: He's never let me down. Rand Paul is a very special guy as far as I'm concerned."Trump has tweeted several favorable comments about Pompeo, whom he recently dispatched to Pyongyang to meet with North Korean ruler Kim Jong Un in advance of Trump's planned summit with Kim over denuclearization of the Korean peninsula."Mike Pompeo is outstanding. First in his class at West Point. A top student at Harvard Law School. A success at whatever he has done. We need the Senate to approve Mike ASAP. He will be a great Secretary of State!" Trump said.