1) As readers of this blog know, recalls frequently result in a big boost to the target, especially if they survive. I was talking about this during the 2012 VP selection chatter, and thought Walker could be a top candidate for the job. Obviously, he wasn't chosen, but the logic still holds.
2) Midwest Governors are always talked about as presidential candidates, but they rarely get there -- Stevenson's the last to get a nomination, and the Idol of Ohio, the originator of McKinelynomics , William McKinley was the last to win.
3) Here's what I think is the crux of this piece -- the sheer volume of mentions in the WSJ/NYT of Walker compared to other governors of much larger and more economically important states (see that below). I would have really loved to figure out a search on Fox News for this (as I think they would have had a larger impact on the target audience than any other news source), but I have no idea how to perform that search on a free engine. Similar problems prevented me from expanding this to the LA Times and the Washington Post. The February 5 date was a technological limitation -- I would have liked to go back to January 1, 2011, but the WSJ has a four-year time limit.
WSJ/NYT and undoubtedly other papers, wire services, radio and TV stations covered that recall extensively. There are other governors from that area who got significant press (Mitch Daniels most notably), but he was a part of the Great Mentioning, so his press was very different.
Now the results of all of this coverage doesn't mean that Walker was super-well known -- relatively recent polls have shown that the majority of Republicans did not have an opinion about him. But I think his name was out there and in (for Republican primary voters) an extremely positive connotation. This is why Walker is pushing forward.
Therefore, the campaign received massive news coverage–far eclipsing what other governors would get for anything other than a scandal or a serious presidential campaign. A quick search of The New York Times (NYT) and The Wall Street Journal (WSJ) shows this. From February 5, 2011 to December 31, 2012, Scott Walker was mentioned in 422 New York Times and 667 Wall Street Journal stories.
Compare that to some of his fellow GOP governors who were elected at the exact same time from much larger states with far greater economic impact on the country. Ohio’s John Kasich received mentions in 64 NYT and 167 WSJ pieces. Michigan’s Rick Snyder saw his name in 105 NYT and 196 WSJ stories. Florida’s Rick Scott was mentioned 214 times by the NYT and 152 times by the WSJ. And Pennsylvania’s Tom Corbett appeared in 68 NYT and 117 WSJ articles.