Candidates in three of the races that could determine control of the Senate engaged in bitter and personal attacks.

© Pool photo by Paul Sancya

Candidates in three of the races that could determine control of the Senate engaged in bitter and personal attacks.

© Pool photo by Paul Sancya

The second debate between Senator Susan Collins, a vulnerable Republican, and Troy Jackson, her Democratic challenger, quickly grew heated.

Senator Jon Ossoff, a Democrat, called his Republican opponent, Representative Mike Collins, a bigot. Mr. Collins called the incumbent a radical “trust-fund kid.”

Plus, a big debate night in Senate battlegrounds.

© Jamie Kelter Davis for The New York Times

In a top Senate battleground, Representative Ashley Hinson, the Republican nominee, sparred with Josh Turek, her Democratic rival, on policy issues ranging from Medicaid to term limits.

© Pool photo by Cody Scanlan

Senator Susan Collins, one of the most vulnerable Republicans in the midterms, clashed with the Democratic challenger Troy Jackson over President Trump, ICE and more.

© Ryan David Brown for The New York Times