Gov. Kristi Noem of South Dakota and the entrepreneur Vivek Ramaswamy tied for the top choice to be former President Donald J. Trump’s running mate in a straw poll on Saturday at a prominent gathering of conservative activists.

The straw poll at the 2024 Conservative Political Action Conference was the first time in years that a question about whom Republicans should pick for vice president had overshadowed one about the presidential nominee in the survey of attendees.

That was partly because Mr. Trump won the presidential poll, as expected, in a landslide. The last time Mr. Trump was not the top choice for the White House among CPAC attendees was in 2016, when Senator Ted Cruz of Texas finished first.

The straw poll, which provides one measure of enthusiasm on the far right and is not intended to be predictive, was announced at the end of the four-day CPAC gathering outside Washington.

Several Republicans viewed as contenders to be Mr. Trump’s running mate gave speeches at the event. They included Representative Byron Donalds of Florida on Thursday; Ms. Noem, Senator J.D. Vance of Ohio and Representative Elise Stefanik of New York on Friday; and Kari Lake, an Arizona Senate candidate, on Saturday. Mr. Ramaswamy spoke on both Friday and Saturday.

Ms. Noem and Mr. Ramaswamy each garnered 15 percent of the vote in the straw poll. Former Representative Tulsi Gabbard of Hawaii, who ran for president as a Democrat in 2020 but has since left the party to become an independent, was third with 9 percent, trailed by Ms. Stefanik and Senator Tim Scott of South Carolina with 8 percent each.

“It feels like I’m the only one who isn’t running for vice president,” said Tom Fitton, the president of the conservative group Judicial Watch, who spoke at the conference. “Although — who knows what will happen.”

The attention on the vice-presidential question was also notable because Mr. Trump is still fending off a challenge for the Republican presidential nomination by former Gov. Nikki Haley of South Carolina. He has won the party’s first several nominating contests and is widely expected to prevail again on Saturday in Ms. Haley’s home state.