Rep. Maxine Waters is coming for Donald Trump. 

The outspoken California Democrat tweeted an update Tuesday on her quest to remove the president from office, writing simply "Get ready for impeachment." And people were reading: Within four hours, the tweet had 2,900 responses, 12,000 retweets and 30,000 likes.

Read: President 'Dangerous To The United States,' Democrat Maxine Waters Says

The message came a day after FBI Director James Comey testified before the House Intelligence Committee that the agency was investigating the possible ties between the Trump campaign and Russian officials during the 2016 general election. After Comey confirmed the probe, Waters released a statement calling for an independent investigation, condemning the director for not taking action to curb Russia's influence last year and instead focusing on Democrat Hillary Clinton's use of a private email server while secretary of state.

"My takeaways: Donald Trump is a liar & the FBI Director still has no credibility," Waters tweeted. "He needs to also explain HIS interference in the election."

Waters, serving in her 13th term, has ramped up her criticism of Trump in the two months since his inauguration. She's repeatedly said she believes Trump is "leading himself" into legal trouble — despite House Minority Leader Nancy Pelosi's reticence to definitively say Trump should be impeached.

"When I've talked about leading him to impeachment, what I'm really saying is he has done enough in the short period of time for questions to be raised about whether or not he's acting in the best interest of this country," Waters said in a video posted Feb. 6.

Read: Betting Odds Indicate POTUS Will Likely Be Removed In First Term

Only two presidents have ever been impeached, Andrew Johnson in 1868 and Bill Clinton in 1998, but neither of them was removed from office. Constitutionally, the president, vice president and any civil officer can be impeached for treason, bribery or "other high crimes and misdemeanors."