With the arrival of the pope, our spirits lift.

With the departure of Scott Walker, they plummet.

There’s so much we’ll never know, such as how far he was willing to take his single issue. For Walker it was unions at dawn, unions at dusk, unions in his dreams. Having hobbled them in Wisconsin, he vowed to cripple them nationally, and who’s to say it would have stopped there? I feel certain that he was mere weeks away from a big speech advocating the deployment of ground troops to stamp out collective bargaining among the Sherpas in Nepal.

I feel certain, too, that his best gaffes were still to come, though he gave us several gems. In an era lacking visionary leadership, he envisioned a great wall along our northern border to keep out the tides of Canadians fleeing the tyranny of free health insurance. And we learned that years back, he mangled an intended “mazel tov” in a letter to a Jewish constituent, instead writing: “Thank you again and Molotov.”

I miss him already. And I wonder: Was it his shallowness that undid him? Just how little learning will Republican voters abide in a candidate? Did he test the limit?

One of his former aides, Liz Mair, suggested as much, firing off tweets on Monday about his errors, including “not educating himself fast enough” on national and world affairs.