WASHINGTON – Alan Grayson will announce Tuesday he'll challenge Congressman Darren Soto of Orlando, taking on a fellow Democrat he faults for not joining in a push to impeach President Donald Trump.

"The people who are appalled by the Trump presidency are demanding it," Grayson told the Tampa Bay Times prior to filing candidate papers. Soto has not joined liberals in voting to proceed with impeachment.

"The district is, if anything, more anti-Trump than the country by a significant margin," Grayson said. "These are critical times. I mean, the president is trying to dismantle democracy."

Party leaders have worked to quiet impeachment talk — Republicans are fashioning it into a rallying cry – but grassroots activists want to see it happen. "I think there are a lot of Democrats who are in fact concerned that there is not enough leadership and spine in the party to stand up to the bullying president."

Grayson as a U.S. Senate candidate in 2016 faced allegations of spousal abuse and got into an altercation with a Politico reporter. Liberal groups withdrew endorsements and party leaders hoped he'd go away for good.

But Grayson has continued to raise money and points to a record and built under three House terms, highlighting attempts at gun control and work on issues facing seniors.

"It's up to the voters. It's not up to the party," he said.

The 60-year-old hasn't concealed his comeback ambitions but did not reveal which district he would run in, until now. He had nearly $700,000 in a campaign account as of the end of March. Soto had $364,000.

"We've looked at the numbers, we've polled it and my support is strongest in my old district," said Grayson, adding he performed well there in the Senate primary against Patrick Murphy.

Soto, the first Puerto Rican from Florida in Congress, will kick off his re-election campaign Thursday in Kissimmee. He's backed by all other Democrats in the Florida House delegation.

"Mueller must finish his investigation before we can properly vote on impeachment," Soto told the Times. "If he finds Trump has committed crimes, I would be more than happy to vote for impeachment."