Political observers say Obama remains the odds-on favorite to win Wisconsin’s 10 electoral votes, a sentiment reflected in exit polls showing the president leading Mitt Romney by a healthy margin.

But they say Team Obama should be shaken by the recall results, which highlighted a strong GOP ground game — including the influx of corporate and special-interest money — headed into the November election…

The result energized Republicans across the country — even in the liberal bastion of San Francisco. Obama, visiting the City by the Bay for a fundraiser on Wednesday, was greeted by signs reading, “As goes WI goes the USA” and “The People 1, Unions 0,” according to a pool report…

In an email to supporters, Obama campaign manager Jim Messina called Tuesday’s outcome — and, more specifically, the super-PAC money spent on Walker — a “terrifying experiment.”