Suozzi was the County Executive of Nassau County, New York, in office from 2002 to 2009. He was first elected to the post in 2001 after four terms as mayor of Glen Cove, New York. In 2006, he ran unsuccessfully against Eliot Spitzer for the Democratic nomination for Governor of New York. Suozzi was narrowly defeated for re-election in 2009 by Republican nominee Ed Mangano, and in a rematch in 2013 was again defeated, this time by a much larger margin of 59% to 41%. He was first elected to United States House of Representatives in 2016 narrowly and reelected in 2018 and 2020.