PORTLAND, Maine - Democratic Senate candidate Troy Jackson told Republican Sen. Susan Collins to "shut up" during a heated final Maine U.S. Senate debate that also included an interruption from a data center protester.

Thursday night's debate in a Bangor theater was the last of four meetings between Collins and Jackson, who are running for a seat that's considered crucial in the fight for a Senate majority.

The debate, like those that preceded it, included several testy exchanges over issues including the national debt, Collins' relationship with President Donald Trump's administration, and the candidates' respective roles in worsening partisan divisions.