"He would consider looking at it in the middle of October, and decide by the end of the year," Vander Plaats's spokesman, Dave Barnett, tells Buzzfeed.

The Iowa Republican primary field is already crowded, with four lesser-known candidates in the race. Vander Plaats has said for months that if no candidate emerged from the pack in fundraising or polling by the end of the September fundraising quarter that he'd be "very open" to running.

"Most of the candidates are largely unknown to Iowans. We've just got to let this play out, let the process play out," he said then. "I've been very open. Labor Day we'll see who's catching fire, on October 15 we'll see who's raising money."

Vander Plaats has run for office multiple times before, losing the GOP nomination for governor in 2002, 2006 and 2010. Over the years he's developed a powerful network in the state — he led the successful efforts to remove Iowa Supreme Court justices who'd legalized gay marriage in the state. His endorsements of former Arkansas Gov. Mike Huckabee (R) and former Sen. Rick Santorum (R-Pa.) helped both men win Iowa's presidential caucuses.

Iowa Republicans have struggled to land a top-tier recruit to run for retiring Sen. Tom HarkinThomas (Tom) Richard HarkinDem Senator open to bid from the left in 2020 Senate GOP rejects Trump’s call to go big on gun legislation Trump should require federal contractors to follow the law MORE's (D-Iowa) seat in the swing state, while Democrats have coalesced around Rep. Bruce BraleyBruce Lowell BraleyOPINION | Tax reform, not Trump-McConnell feuds, will make 2018 a win for GOP Ten years later, House Dems reunite and look forward Trump: Ernst wanted 'more seasoning' before entertaining VP offer MORE (D-Iowa). Vander Plaats would be a bigger name than those currently running, and he could have a real shot at the nomination, particularly if no candidate reaches the 35 percent needed to win the nomination in a primary and a state convention chooses the GOP nominee.

But his strongly conservative views, especially on social issues, would make him a tough sell in a general election in the swing state.