On Monday, Maryland Democratic Sen. Barbara Mikulski announced that she plans to retire after serving five terms in the Senate.

Carson, who practiced medicine at Johns Hopkins University in Baltimore for more than 30 years, was immediately mentioned by some supporters as an ideal Republican to run for the Senate seat next year. But that doesn’t look like it will happen.

“His focus is on making a decision to run for the presidency,” Carson’s top adviser, Terry Giles, told The Daily Caller.