Control of the Senate Is Still a Jump Ball

This sentence from Nate Cohn in the New York Times is likely to thrill a lot of Republicans who hunger for good news about the upcoming midterms: “That warning sign is flashing again: Democratic Senate candidates are outrunning expectations in the same places where the polls overestimated Mr. Biden in 2020 and Mrs. Clinton in 2016.”

What was most memorable about the 2020 Senate polling were the spectacular misses — Sara Gideon’s consistent polling lead over incumbent Republican Susan Collins in Maine,  and the Quinnipiac polls that kept showing South Carolina Republican Lindsey Graham tied with Democrat Jaime Harrison. Collins won by 8.6 percentage points, and Graham won by 10 points.

There were other smaller-scale examples of the same phenomenon, like North Carolina Republican Thom Tillis eking out a tight victory over Cal Cunningham, and Montana Republican Steve Daines winning by a comfortable 10-point margin after appearing tied or close to tied with Steve Bullock in many polls. In Iowa, a few late polls put Democrat Theresa Greenfield ahead by a small margin; Republican Joni Ernst won by 6.6 percentage points.

When Democrats won key Senate races, they usually – but not always – won by a smaller margin than the late polls indicated.