Rhoden, according to the Rapid City Journal, is considering running and will make a decision sometime over the next few weeks. He told the paper that while he knows it would be a tough race, it's a significant opportunity.

"I know it would be a tall order, especially going up against someone with the high name ID like Mike Rounds," Rhoden said. "But on the other hand, life presents few opportunities like this."

Rounds is favored by the GOP establishment to take the nomination for a seat that looks likely to be an easy Republican pickup, as Democrats failed to nab their top recruit in the race. But he's faced criticism from conservatives, who believe he's too moderate to win the nomination.

Rhoden says he has a more conservative record than Rounds and an outsider appeal he believes voters wary of Washington want.

And now that Rep. Kristi Noem (R-S.D.) has decided against challenging Rounds in a primary, Rhoden says he knows he'll have to decide, "probably sometime next month."

"There are issues we're working on right now, as far as trying to put a team together," he said.