Viewership Fell Sharply for Second G.O.P. Debate

Fewer than 10 million people watched the Republican presidential debate on Wednesday night, according to preliminary data from Nielsen, a sign that interest in the race is waning without the presence of former President Donald J. Trump, the front-runner for his party’s nomination, who has so far refused to participate in the debates.

The audience on Wednesday — viewers of Fox News (6.7 million), Fox Business (1.8 million) and Univision (813,000) — was down from the 12.8 million people who tuned in last month to watch the first Republican primary debate. Fox also hosted that debate.

Those numbers are a fraction of the audiences for the first two Republican presidential debates in the summer of 2015, when a crowded field and curiosity about Mr. Trump pushed ratings to record highs. The first, hosted by Fox News in Cleveland, drew nearly 24 million viewers — ranking among the most-watched events in cable-TV history. The second, hosted by CNN in Simi Valley, Calif., had an audience of 22.9 million.

Without Mr. Trump this primary season, the networks and the Republican National Committee are in a difficult spot. Television executives will be faced with deciding whether it’s worth the cost to produce an event that is drawing relatively tepid interest and is, for the moment, of questionable significance given Mr. Trump’s dominance in the polls. In most national surveys taken since the summer, he has led his closest rival, Gov. Ron DeSantis of Florida, by more than 30 points.

Mr. Trump appears unlikely to agree to appear at any debate in the near future. His campaign said this week that he would not participate in one scheduled for early November in Miami. And one of his senior advisers called on the Republican National Committee on Wednesday not to schedule any more debates for the primary season so Republicans could instead focus on defeating President Biden.

Despite the lower ratings, the debate attracted an audience larger than any other program on cable or network television on Wednesday evening.