Senate Republican Leader Len Fasano, R-North Haven, is not seeking re-election, opening a fight to succeed him in a suburban New Haven district and as leader of the GOP minority in the Connecticut Senate. With Donald J. Trump in the White House and the Democratic base energized, Democrats won 23 of the 36 Senate seats in 2018. The Democratic advantage fell to the current 22-14 after Republicans picked up a seat in a special election last year. As the caucus leader, Fasano both fought and, on occasion, worked cooperatively with two Democratic governors, Ned Lamont and Dannel P. Malloy. And he kept his distance from the president, declining an invitation to be a Trump delegate to the 2016 Republican National Convention.