A wealthy first-time candidate, Dr. Oz is in a bitter, high-priced battle with another superwealthy rival for the G.O.P. nomination, David McCormick, a former chief executive of the world’s largest hedge fund. Both candidates have ardently sought Mr. Trump’s endorsement, both personally and through surrogates, as they have awkwardly remade themselves from middle-of-the-road, establishment Republicans to appeal to Mr. Trump’s hard-right base. Dr. Oz welcomed the endorsement in a statement that said, “President Trump wisely endorsed me because I’m a conservative who will stand up to Joe Biden and the woke left.”
A poll last week by Emerson College and The Hill found a virtual tie between the two candidates among very likely primary voters, with Mr. McCormick at 18 percent, Dr. Oz at 17 percent and 33 percent undecided.
In North Carolina, Mr. Trump repeated his endorsement of Dr. Oz, likening his long television run as proof of political viability. “When you’re in television for 18 years, that’s like a poll.’‘ Mr. Trump said of Dr. Oz, whose show ended a 12-year run in January. “That means people like you.”
The Pennsylvania race, to fill the seat of the retiring Senator Pat Toomey, a Republican, is widely seen as one of the most crucial in both parties’ efforts to win control of the Senate in this year’s midterm elections. Democrats have a hard-fought primary of their own, featuring most prominently Lt. Gov. John Fetterman and Representative Conor Lamb.
After Mr. Trump’s endorsement, Mr. McCormick’s top strategist, Jeff Roe, tweeted that Mr. McCormick is going to be the next Senator from Pennsylvania.