A supporter for outgoing House Majority Leader Eric Cantor (R-VA) threw wine at a protester supporting immigration reform during a confrontation following Cantor's concession speech, the Washington Post reported.

Cantor, who had just been upset by Tea Party-backed challenger Dave Brat in the Republican primary for Virginia's 7th congressional district, was not around for the scuffle, which took place at a suburban hotel ballroom in Richmond.

The immigration advocacy group Casa de Virginia took credit for the demonstration on Twitter, posting, "@CASAdeVirginia storms Cantor "victory" party reminding that Cantor lost because inattentive to district meanwhile 89% of 7thCD Rs want CIR."

The acronym "CIR" is short for "comprehensive immigration reform," which progressive groups have said has stalled in the House under Cantor and Speaker John Boehner's (R-OH) leadership.

"Eric Cantor lost because he was a pretend Tea Partier," Casa de Virginia organizer Lindolfo Carballo was quoted as saying. "But voters, faith and business leaders, and more all agree that we need a real leader to end the suffering of our families."

WTVR-TV reported that the demonstration began when a protester took the stage and began yelling about immigration reform.

The demonstrators, who gathered at an entrance to the ballroom, chanted "What do we want? Immigration reform. When do we want it? Now," and can be seen in video posted by United Press International below.

Separate footage also shows a member of the hotel's security staff wrap a forearm around a young woman's throat for a few seconds before being convinced to release her. After the demonstrators reached the ballroom, a hotel employee reportedly told them they would be arrested if they did not leave the premises, a request later backed up by police.

As the protest dispersed, another Cantor supporter reportedly yelled, "Get a job" to a demonstrator who was wrapped in the American flag.

Watch footage from the protest, as aired on WTVR, below.