Senate Majority Leader Mitch McConnell (R., Ky.) mocked left-wing "scare tactics" over the years against Republican Supreme Court nominees on Monday, saying "it's hard to keep a straight face" with some of the recent rhetoric against President Donald Trump's unnamed choice.

Trump has made his decision to fill the vacancy left by Justice Anthony Kennedy's retirement, and he will announce it from the White House at 9 P.M. ET on Monday night.

Without naming him, McConnell noted Sen. Bob Casey (D., Pa.) had already declared he would oppose whatever judge Trump picked based on the list of his finalists. Trump also quoted Sen. Kamala Harris (D., Calif.), who said on MSNBC that "we're looking at the destruction of the Constitution of the United States" with Kennedy's retirement.

McConnell chuckled as he read the quote on the Senate floor.

"It's hard to keep a straight face when you hear stuff like that," McConnell said. "There's not even a nominee yet. Justice Kennedy just announced his retirement, and they're talking about the destruction of the Constitution? Please, give the American people some credit."

"This far-left rhetoric comes out every single time, but the Apocalypse never comes," he added. "Americans see beyond … this kind of fear-mongering they tried over and over again for 40 years. Senators should do the same."

McConnell also quoted old attacks on Republican nominees from Democrats and progressive allies.

"Sexist. A disaster for women. Totally unacceptable," he said. "These are just a few of the ad hominem attacks the far-left special interest groups hurled at a federal circuit court judge whom a Republican president nominated to the Supreme Court. The name of the federal judge? Anthony Kennedy."

Believe it or not, McConnell said of Kennedy's confirmation, "the sky didn't fall."

"But decades later, our Democratic colleagues still haven't tired of crying wolf whenever a Republican president nominates anyone, anyone, to the Supreme Court," he said. "Decade after decade, nominee after nominee, the far-left script hardly changes at all. Anyone and everyone a Republican president nominates to the Supreme Court is some kind of threat to the republic."

McConnell said "scare tactics" had even been used by the left against former Supreme Court Justices David Souter and John Paul Stevens, who were nominated by Republican presidents George H. W. Bush and Gerald Ford, but wound up consistently siding with the Court's liberal flank.

McConnell infuriated Democrats in 2016 when he announced there would be no hearing or vote on Merrick Garland, President Barack Obama's Supreme Court pick to fill the vacancy created by Justice Antonin Scalia's death. In response to Democratic charges of hypocrisy over him giving a vote to Trump's nominee in 2018, he said he made it clear that his decision in 2016 was because it was a presidential election year.

Monday's announcement will mark Trump's second Supreme Court nomination in as many years. He nominated Neil Gorsuch last year, who was ultimately confirmed on April 7, 2017.