With post-debate polls showing Donald Trump still in the lead for the GOP presidential nomination, frustration is beginning to boil over at what Sen. Rand Paul dubbed Monday the "fake conservative."

In a column and in a late afternoon call with reporters, Paul joined others and assailed Trump, not for his distasteful comments about Fox News host Megyn Kelly, but for his flip-flopping on conservative issues over the past several years.

"I honestly have no idea what Mr. Trump's real philosophy is. He was liberal before he was conservative, and has openly professed for decades that his views are those of a Democrat," he wrote in a column for The Journal by IJR Review.

He added: "This is a guy who said in 1999 that he was a strong supporter of the United Nations. He was for partial birth abortion before he was against it. He lavished praise on the bank bailouts. He was for Obamacare before he was against it and has said he's 'liberal on healthcare.'"

Later today, he added that Trump is not supportive of Tea Party issues, though it appears in polls that the Tea Party likes Trump.

"It makes me sad to think that Tea Party awakening could be hijacked or hoodwinked by a guy who supported the bank bailouts, supported Obamacare and continues to support the Clintons," said Paul.

Trump's rise in the polls has confounded the other candidates, the Republican National Committee and most of Washington. But his supporters claim it's easy to understand: They are sick and tired of Washington and its politicians.

But Paul said that Trump doesn't stand for anything. "Someone needs to point out that the truth-telling is that the emperor has no clothes," he said.

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at pbedard@washingtonexaminer.com.