Wisconsin Governor Scott Walker appeared on the Charlie Sykes radio show in Wisconsin and endorsed …

Ted Cruz.

It was a very strong endorsement for Cruz, not an anti-Trump endorsement. Walker said he was “all in” for Cruz.

Scott Walker Statement Endorsing Ted Cruz

This is not a big shock, and was the focus of speculation for a couple of weeks.

I doubt this will affect national numbers, but will be important for the Wisconsin April 5 primary. Above all else, it will help motivate and get out the rank and file who helped Walker overcome the Democratic onslaught over the union reform bill and recall challenge. It also may help keep Kasich from being a spoiler.

There are 42 delegates at stake. The statewide winner gets 18, then there are 3 each for the winner of each congressional district.

Cruz has been on the ground in Wisconsin building a Walker-style voter turnout model, while Trump is just showing up:

Donald Trump is planning to make his first campaign visit to Wisconsin on Tuesday, where the upcoming Republican presidential primary could mark a turning point in the unpredictable GOP race.

But rival Ted Cruz has gotten a jumpstart on the contest, racking up influential endorsements, campaigning in key regions and supported by bullish advertising campaign….

As Cruz campaigned across the state ahead of the Easter holiday, he was following a winning roadmap drawn by Wisconsin governor – and former 2016 presidential hopeful – Scott Walker in 2010, up Wisconsin’s rural and working-class midsection -the same demographic that has driven Trump’s success thus far.

Cruz has mined the GOP vote-rich swath of farms and factories from south-central Wisconsin, up the Fox River Valley’s corridor of paper mills, small towns – among them, some of the most swing-prone counties in the country.

The Fox River Valley, suburban Milwaukee and the rural counties outside Madison are home to 75 percent of Wisconsin’s most reliable Republican primary voters, said Keith Gilkes, a veteran Walker adviser who worked for his 2010 GOP primary campaign.

There isn’t a lot of polling for the Wisconsin Republican primary; the two most recent polls show Cruz up slightly.

Conservative talk radio in Wisconsin is solidly behind Cruz, including Sykes, who endorsed Cruz. Sykes had a brutal interview with Trump the other day, in which he pressed Trump about his mocking of Heidi Cruz.

The interview has been described Trump walks into #NeverTrump radio buzzsaw:

For 13 minutes, Donald Trump clashed with Milwaukee radio host Charlie Sykes on his program Monday morning, defending his past statements and policy positions. Less than four minutes before the 17-minute interview wrapped, Trump found out why.

“Mr. Trump, before you called into my show did you know that I’m a #NeverTrump guy?” asked Sykes, a Ted Cruz supporter who has vowed to never vote for the New York billionaire.

“No, I didn’t know that, but I assume you’re also an intelligent guy. I know you’re an intelligent guy, and you understand what’s going on,” Trump said. “Our country is getting ripped off by every country we do business with.”

Sykes will not get another interview with Trump after this, and he must have known it going into the interview.

But Sykes didn’t care, since unlike the mainstream cable media, he’s not looking to Trump to pump ratings, so he could do the type of interview  cable media won’t.

If Cruz wins big in Wisconsin, it would be a big blow to Trump’s chances of getting a majority of delegates prior to the convention.