How Democrats’ Senate Dreams Crumbled

Maine House Speaker Sara Gideon had led GOP Sen. Susan Collins in polls ― public and private, Republican and Democratic ― for months. Her likely victory over the longtime incumbent was a key building block in Democrats’ plan to retake the Senate after six years in the minority.

But in the final weeks of the 2020 election, Democrats started to worry. Their internal polls showed Collins not only fighting back, but closing the gap with Gideon. In the days leading up to the election, Senate Minority Leader Chuck Schumer...