MACKINAC ISLAND, Mich. (AP) — A two-man field of Republicans jockeying to challenge Sen. Debbie Stabenow in 2018 could soon double in size.

Rep. Fred Upton, who has held southwestern Michigan’s congressional seat for 30 years, took more steps toward a Senate run at the GOP’s biennial leadership conference this weekend on Mackinac Island. While he has yet to make a final decision, numerous Republicans expect him to join the race.

Upton says he’s a “bipartisan guy” who gets “the job done.”

Another likely candidate, Grosse Pointe businessman Sandy Penser, said he is “pretty confident” he can bring something to the contest, is prepared to spend a lot his own money and will decide within a month. Declared candidates are ex-state Supreme Court Justice Bob Young and Iraq War veteran and business executive John James.