The U.S. Republican Party must be cautious about the dangers of "Trumpism," former Republican House Speaker and onetime vice presidential nominee Paul Ryan said late Thursday Eastern time at the Ronald Reagan Presidential Library.

Ryan, 51, has rarely criticized former President Donald Trump but during this speech he told Republicans not to be overly beholden to one person - or those who act like him. "So, once again, we conservatives find ourselves at a crossroads," Ryan said.

Despite almost regaining the House, the Republican Party has been left powerless following last year's general election -- losing both the presidency and the Senate, he said. "Even worse, it was horrifying to see a presidency come to such a dishonorable and disgraceful end."

"And here's one reality we have to face: If the conservative cause depends on the populist appeal of one personality, or on second-rate imitations, then we're not going anywhere." Voters are not impressed by cadres of yes men and "flatterers flocking to Mar-a-Lago," he said. Mar-a-Lago is Trump's Florida resort.

Ryan criticized President Joe Biden's tax policies and said his first six months in office had been a failure. He said Americans had wanted to elect "a nice guy" who would depolarize politics by moving to the center but instead elected a man "pursuing the most leftist agenda of his lifetime."

Ryan said being the opposition was an opportunity to unite a conservative movement that had achieved goals going back to the Reagan administration.

He did praise Trump for bringing new voters to the Republican Party but noted that he was no longer president and their concerns that caused them to flip still exist. "Take the populace energy of recent years, combine it with the core principles of conservatism and the result will be a coalition even broader and stronger than yesterday's Republican Party," he said.

Ryan also said Republicans should move away from "every little cultural battle" because they distract from traditionally uniting policy issues. "As the left gets more 'woke,' the rest of America is getting weary," he said. "This stuff is exhausting."

Ryan was criticized in 2019 by Trump, who said his record as House Speaker was "atrocious" and that he was a "lame duck failure."