Donald Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE on Tuesday called Rep. Trey Gowdy Harold (Trey) Watson GowdySunday shows preview: Election integrity dominates as Nov. 3 nears Tim Scott invokes Breonna Taylor, George Floyd in Trump convention speech Sunday shows preview: Republicans gear up for national convention, USPS debate continues in Washington MORE’s (R-S.C.) hearings on the Benghazi terrorist attack this fall “a disaster” for Republicans.

The GOP front-runner offered the opinion just after Gowdy appeared in Iowa with Sen. Marco Rubio Marco Antonio RubioOvernight Defense: Pentagon redirects pandemic funding to defense contractors | US planning for full Afghanistan withdrawal by May | Anti-Trump GOP group puts ads in military papers Democrats step up hardball tactics as Supreme Court fight heats up Press: Notorious RBG vs Notorious GOP MORE to give the Florida Republican his official presidential endorsement.

Trump responded shortly after the Iowa event.

ADVERTISEMENT

“I hope @TGowdySC does better for Rubio than he did at the #Benghazi hearings, which were a total disaster for Republicans & America!” he tweeted.

Democratic presidential front-runner Hillary Clinton Hillary Diane Rodham ClintonDemocratic groups using Bloomberg money to launch M in Spanish language ads in Florida The Hill's Campaign Report: Presidential polls tighten weeks out from Election Day More than 50 Latino faith leaders endorse Biden MORE testified before Gowdy's panel in October. The grueling day of testimony is now seen as a positive moment for Hillary, as Republicans on the panel were unable to produce any significant revelations.

Since the testimony and a strong initial debate performance, Clinton has been seen as an even bigger favorite to win the Democratic presidential nomination.

Trump had already stepped up his attacks on Gowdy after news emerged late last week of the endorsement.

The real estate mogul and his campaign team, however, haven’t always been critical of the South Carolina congressman.

Before working on Trump’s campaign, Trump adviser Katrina Pierson — while working for the Tea Party Leadership Fund — praised Gowdy and even urged supporters to donate and sign a petition to encourage Gowdy to run for Speaker of the House.

ADVERTISEMENT

Gowdy’s endorsement for Rubio is seen as a boost for the presidential candidate that could be especially valuable in South Carlina, which hosts a primary on Feb. 20.

Trump leads national polls and state polls in New Hampshire and South Carolina.

He holds 35.6 percent support compared to 11.6 percent for Rubio according to the RealClearPolitics average of national polls.