Former Vice President Joe Biden's campaign for the Democratic presidential nomination is "almost finished already," but Democrats pushing for President Donald Trump's impeachment will end up killing it altogether, leaving the path open for Sen. Elizabeth Warren, D-Mass., David Stockman, the director of the Office of Management and Budget under President Ronald Reagan, said Wednesday.

"What this means is that the geniuses in the House Democratic Caucus are going to finish off Biden," Stockman told Yahoo Finance. "When you get into a deep investigation of this, the Republican think tanks will be coming the other way. Biden is almost finished already, this will kill him off . . . there's a question whether he still has all his faculties left but this will take him down."

Meanwhile, there is nobody left to take the nomination but Warren, who plays well in the polls. If she is nominated, that will "scare the living daylights" out of Wall Street when it figures out she might become president, Stockman said.

Stockman said he has read the document from the White House detailing the telephone call between Trump and Ukraine President Volodymyr Zelenskiy, and he has listened to a tape four times of Biden on a public stage "bragging about how he threatened the Ukrainians" with losing aid if a prosecutor general investigating a business that was paying Hunter Biden was not fired.

"This is just another Washington clown show," he said. "It's more ludicrous really that even Russia Gate, which turned out to be a nothing burger."

However, Stockman said Trump's "terrible" policies are the real issue, not "some stupid phone call."

"The trade war is a disaster, the border wars are demented, [and] the fiscal situation is out of control," Stockman said. "He's attacking the Fed randomly. He's about ready to start a war in the Persian Gulf."

• GOP's Sasse, Democrats Call Whistleblower Complaint Credible and Troubling
• Top US Spy Chief Denies Report He Threatened to Quit If Pressured on Testimony