Five months before Election Day, you'd think there would be no better harbinger about who will win the White House than a contentious statewide vote in a critical battleground state that never moved on from the 2010 campaign.

You'd be wrong.

Yes, there will be tea leaves to read after Wisconsin voters decide Tuesday whether to recall rookie Republican Gov. Scott Walker, a tea party-supported GOP hero who might be the only politician in America to rival President Barack Obama in contentious achievement that inspires loathing among opponents...