Trump foe: Enough dirt to 'knock Trump Tower down'

He's coming at Donald Trump like a wrecking ball.

A top backer of Hillary Clinton's Democratic presidential campaign reportedly has said that he has dug up enough dirt on the Republican front-runner to "knock Trump Tower down to the sub-basement," according to a report in Politico.

Republican presidential candidate Donald Trump
Joe Raedle | Getty Images
Republican presidential candidate Donald Trump

David Brock told a group of major liberal donors in California on Monday night that New York real estate mogul Trump hasn't been "properly vetted by his rivals — or the press" so far, Politico reported.

But Brock, who was a conservative journalist and critic of President Bill Clinton in the 1990s, said his American Bridge research group has picked up the slack. Starting all the way back to last summer, Brock said, American Bridge began assembling opposition research on Trump.

Politico reported that Brock, in his prepared remarks, told the Democracy Alliance donor club that his group had "sat on" the material it has collected on Trump to avoid helping other GOP candidates "who might have been stronger general election candidates."

"American Bridge is building a database of all the regular people — from unpaid vendors to harassed tenants to defrauded students at Trump University — who got screwed over for one reason only," Brock said, according to the story. "They took Trump at his word." The Trump campaign did not immediately respond to a request for comment.

"Brock asserted that, if Trump does win the GOP nomination 'a bare-knuckles campaign is necessary' to brand him as a greedy, misogynistic racist, and "a danger to the Constitution, a menace to democracy, and a threat to the nation as a whole," Politico wrote.

But if Texas Sen. Ted Cruz gets the Republican nod, Brock said, American Bridge will frame him as someone "who wants to evict immigrant families, deny women access to health care, cut taxes for the rich and bomb the Middle East 'until the sand glows.'"

The well-heeled crowd who listened to Brock's speech at the Fairmont Hotel in Santa Monica, California, reportedly included Paloma Partners hedge fund founder Donald Sussman, Taco Bell heir Rob McKay and health-care entrepreneur Paul Egerman.

Read the full Politico story here.