Via USA Today:

President Obama seems to be inserting himself into the Republican presidential race, blasting Wisconsin Gov. Scott Walker over a new state law that prohibits requiring workers to pay union dues.

“I’m deeply disappointed that a new anti-worker law in Wisconsin will weaken, rather than strengthen workers in the new economy,” Obama said in a statement issued late Monday by the White House.

It’s relatively unusual for the administration to weigh in on a state law with a formal statement.

Walker, who is expected to seek the Republican presidential nomination next year and is doing well in early polls, says the new “right to work” law will help attract new businesses to the state.

“This sends a powerful message across the country and across the world,” Walker said in signing the new law Monday. “‘Wisconsin is Open For Business’ now is more than just a slogan — it’s a way of doing business.”