Laura Gillen, an attorney from Rockville Centre, defeated Hempstead Town Supervisor Anthony Santino Tuesday to become the first Democrat to ever win that office.

"I really did believe I was going to win," Gillen told News 12 Long Island. "I kind of felt like everything was trending the right way and that people were frustrated."

Santino had openly fought with two fellow Republican Town Board members, Erin King-Sweeney and Bruce Blakeman. The feud included nasty exchanges at public meetings. That led to them both endorsing the Democratic candidate. 

WATCH: Extended interview with Laura Gillen after election win 

"There was no doubt that the residents saw what was going on in the Town of Hempstead at our Town Board meetings. The supervisor was a dictator, clear and simple," said King-Sweeney.

Gillen says she doesn't believe there is a Republican or Democratic way to run a municipality. 

"There's a good way and there's a bad way. And what we've had is a bad way," said Gillen. 

Hempstead is the largest township in the country, with more than 750,000 residents. It has also always been the major source of power for Nassau Republicans.

Santino issued a statement congratulating Laura Gillen on her victory and pledged to work together to ensure a smooth transition when she takes office.