At a 90-minute rally in Ohio on Thursday, President Trump touted the strike that killed Iranian General Qassem Soleimani one week earlier and criticized Democrats' response. Earlier Thursday, the House of Representatives passed a resolution to curb his military powers regarding Iran.

"We got there very early, we saw what was happening — I saw what was happening, I said what's all that about," Mr. Trump said. "And that was going to be another Benghazi. Had they broken through the final panels of glass, they were breaking it, breaking it. Had they gotten through, we would have had either hundreds of dead people or hundreds of hostages. That wasn't going to happen. And I called up our great generals, I said get them over there now."

He also doubled down on claims that Soleimani was "actively planning new attack."

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Mr. Trump criticized House Democrats for calling for him to ask for prior authorization, saying "we had to make a decision." He said he didn't have time to call "crazy Nancy," who he said is "not operating with a full deck." He called Congressman Adam Schiff "crooked Adam Schiff," and said he probably would have leaked it to the press.

Mr. Trump also knocked the Democratic presidential candidates, saying "you have some real beauties," hitting Senators Bernie Sanders and Elizabeth Warren, as well as Pete Buttigieg. " He called it "my job" to watch the Democratic debates, but said "it's like watching death."

Mr. Trump touched on impeachment, saying "they don't even know what the hell is going on" and insisting the case against him is "so weak" that Pelosi won't send over the articles of impeachment.

Thursday's rally was Mr. Trump's first campaign rally of 2020. He insisted "we have to win in 2020 because all of these things that we've done, can be un-done. And you can have a country that goes to hell very, very fast. very very fast."

Fin Gomez contributed to this report.