A second Republican on Sunday entered the fray to battle Donald Trump for the party's presidential nomination in 2020 - an indication of the simmering dissent and division among GOP faithful.
Former Illinois congressman Joe Walsh, 57, threw his hat in the ring in an appearance on the weekly US political talk shows, joining moderate former Massachusetts governor Bill Weld, who announced his candidacy in April.
Walsh was a foot soldier in the Tea Party revolution of 2010, helping push the Republican establishment in a more radical, anti-immigrant and populist direction -- opening the door for Trump's eventual ascent to seize the nomination in 2016 in defiance of the party's mainstream.
Following his unusual rise to power, the president now presides over a solid base of support that seems nearly impervious to the controversies he constantly generates.
But Walsh, who is now a conservative talk radio host, says he is ready to do battle.
"I'm running because he's unfit. Somebody needs to step up and there needs to be an alternative," Walsh said on ABC's "This Week." "The country is sick of this guy's tantrums. He's a child."
"I think that is terrific," he said. "It's going to be a more robust conversation." Like Walsh, he was unsparing in his criticism of Trump, blasting him for "his extreme malignant narcissism" and saying the president is "only happy when other people are losing."