As the House of Representatives cast the deciding votes to impeach President Trump on Wednesday, the number of people watching cable news was far greater than usual, according to Nielsen.

Roughly 11 million people tuned into the big-three cable news channels, Fox News, CNN and MSNBC, from 8 to 9 p.m. Eastern Standard Time, significantly more than the average of 5.7 million viewers who watch at that time on a typical night.

The opinion host Tucker Carlson, who called the impeachment “a disgrace,” was the lead on-air personality on Fox News as the House members cast their votes. He was joined for a time by the anchor Bret Baier. The Wednesday episode of Mr. Carlson’s 8 p.m. show trounced its cable-news rivals, averaging five million viewers during the hour, a 67 percent increase from the usual “Tucker Carlson Tonight” audience.

At the same time, MSNBC drew 3.2 million viewers, better than the 1.7 million viewers who usually watch the channel at that hour. Brian Williams and Nicolle Wallace anchored the hour, and the usual 8 p.m. MSNBC host, Chris Hayes, offered commentary in favor of impeachment.