David Brock said: If Trump is the nominee, “a bare-knuckles campaign is necessary.” | AP Photo Brock: Enough opposition research to ‘knock Trump Tower down’

David Brock, in a Monday night speech to some of the biggest liberal donors in the country, boasted that his researchers had assembled a trove of opposition research on Donald Trump that Democrats could use to “knock Trump Tower down to the sub-basement.”

Speaking at a reception on the sidelines of the annual spring meeting of the Democracy Alliance liberal donor club at Santa Monica’s tony Fairmont Hotel, Brock said that Trump “was not properly vetted by his rivals — or by the press” during the Republican presidential primary.


But Brock, who is a leading supporter of Democratic presidential front-runner Hillary Clinton, said that his non-profit opposition research outfit American Bridge started researching Trump last July, and has unearthed some damning stuff.

“We sat on it all so as not to help the candidates who might have been stronger general election candidates,” Brock said, according to his prepared remarks, which American Bridge released to POLITICO.

The group, which provides research to Democratic campaigns and party committees, is supported by some Democracy Alliance donors. And sources at the Democracy Alliance meeting said several influential donors attended his reception, including health care tech entrepreneur Paul Egerman, who is close to Elizabeth Warren, as well as Taco Bell heir Rob McKay and New York investor Donald Sussman.

While Brock told the donors that American Bridge also had been building oppo files on other prospective Republican presidential nominees — including Ted Cruz and Paul Ryan — he paid special attention to the Manhattan real estate showman who is leading the GOP delegate race, warning: “Trump won’t be a cakewalk defeat” in a general election.

“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,” said Brock. “They took Trump at his word.”

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.”

American Bridge’s approach to attacking Cruz would be a more traditional “straight-up ideological battle,” against a politician who “isn’t much more than a regional candidate,” Brock told the donors. It would involve casting the Texas senator as an extremist “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.’”

He acknowledged that some Democrats have “jitters” over the prospect that Ryan, the House Speaker, who has vigorously denied interest in the GOP nomination, might nonetheless be convinced to accept it as a consensus candidate at an open convention.

But Brock said his group had already been “dusting off the old Romney and Ryan research books from 2012,” and would work to brand Ryan as “a cookie-cutter career politician” whose policies would hurt the poor and women.

Overall, Brock sounded almost gleeful about the general election odds for Democrats.

Not only did he declare “we are going to win this election,” but he predicted a potentially sweeping victory down ballot. He said “we all have this unprecedented opportunity to build a sustainable progressive majority.”