Dr. Abdul El-Sayed’s call with the former president comes as he tries to win over wary Democrats in Michigan’s high-stakes Senate race.

Mike Rogers, the Republican nominee, has suggested that further scrutiny of the 2020 election was warranted and that voting irregularities sank his first Senate bid two years ago.

© Brittany Greeson for The New York Times

In a New York Times/Siena poll of battleground states, national parties were seen as too far to the right or the left, while nominees were viewed as more moderate.

© John Tully for The New York Times

Representative Ed Case beat Jarrett Keohokalole, a younger progressive, in a race that centered on questions of generational change and the state’s skyrocketing cost of living.

© Alex Brandon/Associated Press