That narrows the field down to the pool of leading current and former Republican governors: Jeb Bush, Bobby Jindal, John Kasich, Rick Perry, and Walker. All of those men have something to recommend them, but “no one checks as many boxes as Walker does,” as an Iowa GOP strategist puts it. Walker has near hero status in the grassroots for taking on Wisconsin’s public sector unions. Cruz talks about taking stands on principle, but he lost his fight. Walker took a stand, was targeted by the full force of the Democratic machine, and stayed alive. He won a recall election with a larger margin than his original victory. He raised $30 million for that race, so he knows how to tap wealthy donors. Social conservatives also consider him one of their own for his pro-life views and his pedigree: His father was a Baptist minister.

Jindal and Perry have supporters in conservative circles, but Jindal can’t match Walker’s union-slaying story and Perry’s accomplishments won’t help him overcome the memories of his disastrous 2012 run. If the incentive is to pick a Christie alternative who can survive, it also helps if the candidate comes from a battleground state—even better if they come from a swing state in the Midwest. Walker also brings helpful connections to Iowa, that early caucus state. Besides governing in nearby Wisconsin, Walker grew up in Iowa. Right now GOP operatives describe the competition in the Hawkeye State as one between Rand Paul (whose forces control the state party) and Sen. Ted Cruz (who excites the base).