President Trump unloaded on Democrats Thursday night for continuing to push the story that he colluded with Russia to win the election and said it's a "demeaning" effort to cheat voters out of the president they chose.

"They can't beat us at the voting booths, so they're trying to cheat you out of the future and the future that you want," he said. "They're trying to cheat you out of the leadership you want with a fake story that is demeaning to all of us, and most importantly, demeaning to our country and demeaning to our Constitution."

Trump flew to West Virginia to hold a rally in front of a friendly crowd on the same day it was reported that special counsel Robert Mueller had impaneled a grand jury in his Russia probe. Experts took the move as a sign that Mueller is stepping up his investigation and may be about to subpoena people in the Trump administration.

The grand jury seemed to immediately ratchet up the pressure on Trump, who has faced questions about Russia since before he took office. But Trump used his rally to go on at length against it Thursday night and said it reflects frustration on the part of Democrats for failing to win the White House.

"The Russia story is a total fabrication," he said. "It's just an excuse for the greatest loss in the history of American politics. It just makes them feel better when they have nothing else to talk about."

Trump said Mueller should instead be investigating the 33,000 emails that his opponent, Hillary Clinton, destroyed. That led to a campaign-style chant of "Lock her up," which Trump heard numerous times during the campaign.

"Most people know there were no Russians in our campaign. There never were," he said to cheers.

"Have you seen any Russians in West Virginia, or Ohio, or Pennsylvania?" he asked. "Are there any Russians here tonight?"

Trump also urged the Senate again to repeal Obamacare, something the Senate had to abandon when it fell one vote short last week toward advancing a partial repeal bill. He thanked Sen. Shelley Moore Capito, R-W.Va., who came around and voted with most Republicans in the failed effort.