Former President Donald J. Trump plans to upstage the first Republican primary debate on Wednesday by sitting for an online interview with the former Fox News host Tucker Carlson, according to multiple people briefed on the matter.

In the past 24 hours, Mr. Trump has told people close to him that he has made up his mind and will skip the debate in Milwaukee, according to two of the people briefed on the matter.

Mr. Trump is notoriously mercurial, and left himself something of an out to change his mind with an ambiguous post on his website, Truth Social, on Thursday. He wrote that he’s polling well ahead of his rivals and added, “Reagan didn’t do it, and neither did others. People know my Record, one of the BEST EVER, so why would I Debate?”

[That makes more sense as a counter-programming move. A rally would be just the same old thing for Trump, but a Tucker Carlson interview might be more of a wild card. Will Tucker be as tough on Trump as he was on candidates in the Iowa forum? Viewers might want to watch that and find out. — Ed]