"Staffers in our 6 Maine offices - and in our D.C. office - are receiving offensive, sometimes vulgar calls - harassing the staff," Clark added in a tweet on Tuesday evening.

Annie Clark, a spokeswoman for Collins, separately gave The New York Times copies of letters and voicemail messages being sent to the senator's offices that included threats.

"Have you seen the emails ... where he talked about Roe v. Wade not being settled law. He [bleeped] lied to you. How [bleeped] naive do you have to be?" the caller in the voicemail says.

The TV station obtained voicemails being left at Collins's offices, including one caller who brought up a 2003 email where Kavanaugh suggested cutting a paragraph out of a draft op-ed that characterized Roe v. Wade as widely accepted among legal scholars as settled law.

Staffers for GOP Sen.(Maine), viewed as a key swing vote in the Supreme Court fight, say they are receiving "vulgar" phone calls over Brett Kavanaugh's nomination."We've had some very abusive callers. ... We've had some very vulgar calls and sort of harassing the staff," Steve Abbot, Collins's chief of staff, told a Maine TV station.

Aides for the moderate senator, on social media and in multiple reports published on Tuesday evening, detailed calls and voicemails Collins's offices have been receiving as the battle over Kavanaugh kicks into high gear ahead of an end-of-the-month Senate vote.

One caller, according to the Times, told a 25-year-old female staffer that he hoped she was raped and impregnated.

The frustration being fielded by Collins's staff comes as outside groups are stepping up their pressure on several swing votes, including Collins. How the group of moderates decide to vote on Kavanaugh's nomination will determine if he is ultimately confirmed.

A crowdfunding campaign aimed at getting Collins to vote against Kavanaugh surpassed $1 million on Tuesday.

The campaign, which is being run by Maine People's Alliance and Mainers for Accountable Leadership, has raised more than $1.06 million as of Tuesday evening.

The groups are pledging to donate the money to Collins's future Democratic opponent if she votes for Kavanaugh. Collins isn't up for reelection until 2020.

Collins has dismissed the effort , comparing it to outside groups trying to "bribe" her into voting against Kavanaugh.

"I consider this quid pro quo fundraising to be the equivalent of an attempt to bribe me to vote against Judge Kavanaugh," Collins told conservative news outlet Newsmax.

The Wall Street Journal published an editorial on Tuesday warning outside groups that they couldn't "bribe" Collins.

When Clark shared the editorial on Twitter, Brian Fallon, a spokesman for the progressive group Demand Justice, seized on it as evidence that the outside pressure was getting to Collins.

"Collins aide now eagerly tweeting out editorials from the *Wall Street Journal* to rebut Maine groups' remarkable crowdfunding success that clearly has Collins rattled," Fallon said

Clark responded by sharing a quote from Collins calling the crowdfunding effort "offensive."