Only a small fraction of recent G.O.P. broadcast and streaming ads mention the president, according to a Times analysis of ad data.

© Kenny Holston/The New York Times

Dr. Abdul El-Sayed’s campaign in Michigan released a new ad highlighting his faith, which Republicans have used to attack him in a tight Senate race.

© Zbigniew Bzdak for The New York Times

With Republicans seen as less likely to hold their majority in the House, the party is focusing more on the battle for the Senate, where it is vastly outspending Democrats on ads.

© The New York Times