Live at 6 p.m. ET from crucial Waukesha County, the last top-tier Republican finally joins the race. Ironically, the most succinct statement of Walker’s appeal to righties comes from the country’s most famous labor leader:

https://twitter.com/BenjySarlin/status/620609385321132036

That’s the sound of a man who lost not one but two electoral brawls in Wisconsin and is still holding his jaw from the pain. If you’re into crushing your leftist enemies, seeing them driven before you, and hearing the lamentations of their women, Walker’s the guy who’s done it and will promise this afternoon to do it again as the GOP’s nominee. The most striking theme in the many, many biographical pieces about him that are circulating today in political media is how many of Walker’s enemies in Wisconsin respect him as a shrewd political operator even while hating his guts on policy. The New York Times, in fact, published a tribute to Walker’s political savvy last week that wondered if a guy as detail-oriented as him even needs a senior strategist for his campaign:

He has held elected office continuously since 1993; the presidential contest will be his 14th campaign. And he comes to the race steeped in the knowledge required of a good political operative: what it costs to compete in swing states; the science of purchasing television advertising time; the art of getting good press.

“If I know Scott Walker, he probably knows the media markets just as well in Iowa, New Hampshire and South Carolina as he does Wisconsin, plus where they spill over into and who has the best ratings,” said Robin Vos, the speaker of the Wisconsin Assembly and an ally of Mr. Walker’s. “While I’m up reading Sports Illustrated and The Economist, he’s doing that kind of research.”…

Mr. Walker’s strategic talents can be an asset. His ability to formulate and convey an effective message helped him win three hard-fought elections for governor in four years, including a 2012 recall election, in an extraordinarily competitive state. And he is doing much the same now: It was Mr. Walker who came up with the best-of-both-worlds formulation he has recently woven into his stump speech — that his hard-charging Senate opponents are “fighters,” and his rival governors who have won difficult elections are “winners,” but he is the rare breed who has done both.

What does a savvy political operator do with a field as crowded as this? Initially it seemed like Walker would run as a Rubio-esque establishment/conservative hybrid candidate, a guy who strayed towards the center on hot-buttons like immigration and maybe gay marriage while reminding righties at every opportunity that he crushed public employee unions in Wisconsin. More and more, though, it looks like Walker will run as a basically orthodox conservative, ceding the center to Jeb Bush and looking to win with a righty coalition of tea partiers and “somewhat conservatives.” What drove him to that decision? In a word, Iowa. Ed already quoted part of this National Journal piece in his earlier post but let me grab another bit of it:

He’s the clear frontrunner in the state, but its socially-conservative electorate has no shortage of alternative options. If Walker refuses to adopt far-right positions, he could quickly bleed support to someone like Ted Cruz, who has been telling his team for months that Walker is “renting our voters in Iowa.” But if Walker remains determined not to be outflanked on the right, his appeal could diminish among moderate voters in New Hampshire and beyond…

“You start in Iowa and lock up conservatives, because if you don’t do that, none of the rest matters,” said one longtime Walker adviser, who requested anonymity to discuss campaign strategy. “It’s much easier to move from being a conservative to being a middle-of-the-road moderate later on.”

Walker’s gradually become the favorite in Iowa due to his social conservatism and his roots in the state. If he disappoints there, odds are good that he won’t win a single early state: New Hampshire is coveted by Bush and other centrists like Christie, who’ll be pouring resources into it, and Walker could have a tough time in South Carolina, which will probably come down to the Iowa and New Hampshire winners, a southern candidate (Huckabee, most likely), and Marco Rubio, who’s eyeing the state as his best shot early on. After that comes Florida, which will be a death match between Bush and Rubio. On the other hand, Walker’s the only guy in the field, I think, who could plausibly run the table of the earliest states. If he does win Iowa, the bounce he gets from that would make him a serious threat to win New Hampshire too, and winning both of those states could roll him right through to victory in South Carolina. So it’s Iowa or bust, and winning Iowa means making sure no one gets to your right. That’s why Cruz is grumbling about him and why Walker’s own team is whispering that he’ll revert to a more familiar center-right posture (maybe even on immigration?) once the state is safely won. He’s going to run as a doctrinaire righty only as long as he needs to. See why DrewM — “I get the feeling conservatives going all in on Walker might be the suckers” — is so worried about him?

Via Newsbusters, here’s the “Morning Joe” panel wondering how much more flip-flopping Walker can do before grassroots conservatives turn on him. Given that their candidate of choice at the moment is Donald Trump, I’m guessing a lot. This is one of the few times in life you’ll hear Steve Schmidt criticizing a Republican in exactly the same terms that Ted Cruz will soon be using.