As more Democrats get on the bandwagon of boycotting President-elect Donald Trump’s inauguration, one lawmaker – Rep. Maxine Waters – took the opposition a big step further Monday and floated the possibility of impeachment.

Waters, D-Calif., is one of at least 53 Democratic lawmakers pledging to boycott the Jan. 20 inauguration, joining Rep. John Lewis and others after he declared Trump an illegitimate president in light of alleged Russian interference in the election.

However, Waters took that charge to the next level in an interview on MSNBC’s “Hardball,” saying if some form of collusion were found between the Russians and the Trump campaign, the question of Trump’s impeachment should be raised.

“If we discover that Donald Trump or his advocates played a role in helping to devise strategy, if they are the ones who came up with 'Crooked Hillary,' if they are the ones who came up with 'she's ill,' 'something's wrong with her energy,' and the way that he basically described her in the campaign, I think that is something that would put the question squarely on the table whether or not he should be impeached,” she said.

Asked by MSNBC host Chris Matthews whether Trump could have committed an impeachable offense before even taking office, Waters doubled down and called for more investigations.

“Well I think at the point that investigations discover and can confirm and document any of that that they had a role in helping to strategize, they had a role in attempting to determine the outcome that in many ways they used the information that they got from DNC when they hacked into our e-mails, etc., if that was used against Hillary Clinton in some ways, yes, I think that's impeachable,” she said.

While Waters and Lewis have been among the most vocal in their opposition to Trump, it's not the first time they've pre-emptively protested an incoming president.

The last time a GOP president was elected – George W. Bush in 2000 – Lewis and Waters both refused to attend his inauguration, with Lewis citing questions surrounding the election. A 2001 Washington Post article reported that Lewis chose not to attend as he “doesn't believe Bush is the true elected president.”

Trump noted Lewis’ past boycott Tuesday morning, calling him out for remarks he made on NBC’s "Meet The Press" on Sunday in which Lewis claimed, incorrectly, this is the first inauguration he will miss.