Wisconsin Gov. Scott Walker speaks Thursday at the Republican National Committtee’s winter meeting in San Diego. (Earnie Grafton/Reuters)

Wisconsin Gov. Scott Walker doesn’t light up rooms when he enters. He is unassuming in that way, a proud cheesehead who wears a battery-powered electric jacket to keep warm at Packers and Badgers football games. He appears a Midwestern everyman, belied only by his burning ambition to be president.

For months, bigger-name Republicans have dominated the headlines — and probably will for some time to come. Jeb Bush’s credentials put him in a strong position, and his stirrings have established the early pace of a race that accelerated from zero to 60 almost overnight. Mitt Romney’s sudden and surprising declaration of interest in running again has added another irresistible element to the evolving story line — along with many questions about a third campaign.

The Republican National Committee keeps a list of prospective candidates, names of those who have been mentioned as possibilities to run in 2016. It totals an astonishing 24 people. The eventual field almost certainly won’t be that big, but right now, at least among those with even an outside chance of being competitive, no one seems intimidated by the candidacy of anyone else.

Candidates fill predictable lanes. Bush and Romney are firmly planted in the establishment lane, which has long been dominant in GOP nomination contests. New Jersey Gov. Chris Christie is there, too, though more challenged if Bush and Romney run. The conservative wing is, if anything, more heavily populated.

Four years ago, Romney claimed he might not have run if Bush had decided to do so. His recent announcement, which appeared aimed at preventing Bush from consolidating establishment money, suggests he isn’t thinking that way now, though he hasn’t made a final decision.

Former Arkansas governor Mike Huckabee and former Pennsylvania senator Rick Santorum, the past two winners of the Iowa caucuses, are both moving toward candidacies. Sen. Marco Rubio, despite sharing a Florida base with Bush, sounds like a candidate. Gov. Rick Perry and Sen. Ted Cruz are from two parts of the Texas conservative movement. Sen. Rand Paul of Kentucky moves inexorably toward a formal candidacy with his amalgam of conservative and libertarian ideas. The list goes on.

In the scramble of the 2016 Republican presidential nominating contest, everyman Walker hopes to be the otherman, a candidate with potential appeal to many of the competing constituencies in a fissured party.

Walker is a contradiction, a boring warrior. He will not win the charisma primary, but he has been hardened by his experiences in office. Whatever miscalculations he made that led to the explosion of protests in Madison four years ago, he now wears proudly his subsequent battles with the forces on the left.

He takes every opportunity to remind an audience, as he did last week at the RNC meeting in San Diego, that he has been, as he tells it, the No. 1 target of big unions and big government constituencies — and that he has defeated them repeatedly.

His résumé as a second-term governor gives him establishment credentials. His confrontational reform agenda in Wisconsin and his wars with labor unions and the progressive left have made him a well-loved figure among many in the GOP’s tea party wing. His potential fundraising network, thanks to three campaigns in four years — and especially the 2012 recall election — is among the biggest in the GOP, if he can truly tap it.

The son of a minister, he speaks easily the language of religious conservatives. When he appeared before the RNC meeting, he made repeated references to the power of prayer and the comfort it provided him through difficult campaign tests.

He told a story. When his friend Rep. Paul Ryan (R-Wis.) was selected as Romney’s vice presidential running mate in the summer of 2012, Walker advised him that people would soon be telling him they would be praying for him. When they do that, he told Ryan, “you need to reach out and touch them, because you will feel the power of God.”

Walker is well situated geographically, one of a group of Rust Belt governors who have been talked about as GOP candidates. Others are Ohio’s John Kasich, Indiana’s Mike Pence and, sometimes, Michigan’s Rick Snyder. Of the group, Walker is the only one moving aggressively to assemble a campaign operation.

The number of battleground states has shrunk in recent years, but geographically the electoral map has expanded. The Rocky Mountain West is far more competitive than it was a decade ago, as are some Southern states. But the Midwest heartland remains critically important in the calculations of any candidate.

Ohio is always a battleground, but Democrats have controlled most other big states in the industrial belt. A Republican nominee who could put into play some of those states — Wisconsin, Michigan, Pennsylvania and maybe even Illinois — would force a recalculation of the Democrats’ current advantage in electoral college math. That’s not to say that Walker could do so, but it would be a calling card he would dangle in front of Republican primary and caucus voters.

His message is a work in progress, not yet as tight or crisp as he will want it to be. His RNC speech was less animated but almost twice as long as one that Perry delivered Friday afternoon. While well received, Walker’s speech did not produce the kind of applause Perry got.

Walker presents himself as an outsider to the nation’s capital and a fresh face in contrast to those with bigger names and longer time in the national spotlight (but who, like Romney and Bush, have been out of office for years). The outlines of his message include the assertion that Washington needs what Wisconsin has gotten under Walker — a reform conservative agenda.

What he did not do when he appeared before party leaders, as some other candidates will do as they go around the country, was say that he could bring the two parties together in Washington, that he would work across party lines to produce harmony and productivity.

He favors a bold and conservative agenda and leadership by a firm hand. He says that voters who don’t agree with all his views still appreciate that style. His state has been deeply polarized around his governorship, but he has managed to prevail at home in spite of that.

There are many questions about a Walker candidacy that go beyond whether he can break through in a field with bigger names and flashier personalities. Is he too much a stolid Midwesterner, too narrow in his Wisconsin grounding. Would he be able to marshal the necessary forces for a national campaign and to let go some of the strategic micromanagement of his own candidacy? Would he be able to withstand the rough-and-tumble ahead?

Walker has focus and determination. His hope may be that he will be long underestimated — a candidate ready to surprise at the moments it counts most.