HERSHEY, Pa. — President Trump told supporters on Tuesday at a rally in Pennsylvania that they were “lucky I became your president” before entering into a screed against House Democrats for introducing articles of impeachment against him, calling the effort “flimsy” and “the lightest impeachment in the history of our country.”
“They’re now admitting there was no collusion,” Mr. Trump said, raising his voice to a shout and accusing Democratic leaders of backing away from specific criminal charges of bribery and extortion they had considered. “They’re impeaching me and there are no crimes. This has to be a first in history.”
Mr. Trump also targeted Speaker Nancy Pelosi’s decision to work with him to complete portions of his administration’s signature North American trade pact, known as the United States-Mexico-Canada Agreement, and suggested that she had done so to “smother the impeachment crap.”
“We’ve been waiting a long time for Nancy Pelosi to announce U.S.M.C.A.,” he said of the agreement, announced by Ms. Pelosi shortly after the articles were released, to strengthen portions of the deal. “And she did it on the same day that they announced that they are going to impeach the 45th president of the United States, and your favorite president.”
The rally gave the president an opportunity to have a lengthy last word — and fire up a portion of his base in a crucial swing state — on one of the most consequential days of his presidency. Hours earlier, House Democrats had formally called for Mr. Trump’s removal from office, announcing two articles of impeachment against him, one for obstruction of Congress and the other for abuse of power. The president, they argued, “ignored and injured the interests of the nation” in his dealings with a foreign government.
With his voice rising and falling as he toggled between pride over a strong labor market and anger over impeachment, Mr. Trump made it clear he took it personally.
“The radical left Democrats,” he said, “are trying to nullify an election and overthrow a democracy.”
He later warned that “any Democrat who votes for this sham will be voting to sacrifice the House majority, their dignity and their career.”
Ticking off other stories surrounding his administration, Mr. Trump denounced a long-awaited report by the Justice Department’s independent inspector general that ruled that F.B.I. officials had sufficient reason to open the investigation into links between Russia and Trump campaign aides in 2016, and acted without political bias.
He took a swipe at the inspector general — an official he singled out for being appointed by “Barack Hussein Obama” — and his handpicked F.B.I. director, Christopher A. Wray, returning to a line of attack from earlier in the day — “You have great people in the F.B.I. but not good leadership.”
The president added that he anticipated reading a report by John H. Durham, a prosecutor appointed by Attorney General William P. Barr to investigate the origins of the Russia investigation.
Before arriving in Pennsylvania, Mr. Trump spent the day on Twitter attacking the substance of the impeachment articles, which seek to outline how he pressured Ukraine to announce a public investigation into former Vice President Joseph R. Biden Jr., a chief political rival, in part by holding up military aid.
House Democrats have also accused Mr. Trump of sowing doubt by promoting an unsubstantiated theory that the Ukrainians, and not Russia, had interfered in the election, an idea that has been discredited by intelligence agencies. In what was either a stroke of defiance or odd timing, the president on Tuesday hosted Sergey V. Lavrov, the Russian foreign minister, in the Oval Office.
The two discussed “election meddling,” Mr. Trump tweeted while en route to the Keystone State.
Mr. Trump spent several weeks this fall holding rallies in an effort to bolster Republicans in state races, emerging with a spotty track record, but Tuesday’s event was solely about him.
On his way out of Washington, he described the articles of impeachment as “weak,” and called the trade deal a “silver lining” that Democrats had agreed to out of “embarrassment.”
“When you look at the poll numbers,” Mr. Trump said, “we’re way ahead of everybody.”
The White House has been closely watching Republican-made polls that show fortunes improving for Mr. Trump in crucial states. He was joined in Hershey by Vice President Mike Pence, who spent the day in Pennsylvania meeting with veterans and supporters. The White House is betting that a strong economy will entice voters to retain a razor-thin Republican majority in a state Mr. Trump won by 44,292 votes in 2016.
Mr. Pence emphasized the president’s support of a defense spending bill that would deliver a 3 percent raise to the military, the appointment of federal judges, “the sanctity of human life” and the president’s continuing battle with “endless investigations” waged by Democrats.
“The truth is, they’re trying to impeach this president because they know they can’t defeat this president,” Mr. Pence said shortly before the president took the stage. “They can’t win against our record, they can’t win against our results.”
In Hershey, Mr. Trump tailored his message to Pennsylvanians by trumpeting the local labor market. But he also sharpened a darker narrative, sharing grisly stories of rape, murder and other crimes he said were committed by undocumented immigrants in Pennsylvania.
“How stupid can you be?” Mr. Trump said as he targeted Philadelphia, where officials have defied the Trump administration’s attempts to target so-called sanctuary cities. “Some officials with these crazy laws that you have.”
As the president continued down his punch list, including a jab at Mr. Biden — “Hey, have you ever noticed where Biden keeps saying he’s in the wrong state? What is wrong with this guy?” — attendees returned the enthusiasm, turning up in homemade gear to meet the moment. They included a man in a bathrobe lettered with the phrase “Impeach My …” and a group of high schoolers in T-shirts emblazoned with “Trump’s Tweets Matter,” in addition to a Santa Claus.
Edwin Frese, 32, an electrician who lives in Harrisburg, Pa., said he had followed the impeachment hearings on the radio at work, but was not persuaded that the president had pressured a foreign leader for a political errand.
“It’s a show trial,” Mr. Frese said, noting that he believed the witnesses had no firsthand evidence. “Even if it goes to the Senate, they’re never going to remove him from office.”