Don't go, Olympia!

Rare is the Democrat of plausible national ambition who tangles in a tough, meaningful way with labor unions or environmentalists, groups that President Obama has been loath to cross. Disappointing them jeopardizes the campaign infantry and financial contributions they provide, and as the sway of interest groups rises, the fealty of politicians to the ones in their corner grows with it.

Rare is the Republican of plausible national ambition who doesn’t kowtow to religious conservatives, a spectacle on florid display during the Republican primaries, including last week, when Mitt Romney signaled support for the Blunt amendment just before Senate Democrats — with an assist from Snowe — defeated it. He may not quite be lighting his hair on fire, to cite his own boast of faux defiance, but there’s ample smoke rising from his fabled mane, as he burns away the Northeastern moderate he was. In fact he used to be Snowe — minus the obvious differences in gender, religion, wealth and pet care. But that was before he reached higher. Before he had much of the independence and many of the idiosyncrasies bled out of him. Before the Republican margin gobbled up the middle and ate a good chunk of Mitt along with it…

There’s less and less room in American politics for a hodgepodge of positions that don’t adhere to one of the two sanctioned scripts. Unsubtle caricatures outnumber complicated characters. That will be only truer with her retirement at year’s end.

It’s a sad, sad thing, and I sympathized with the pleading in the voice of a reporter who asked Snowe on Friday, “Are you sure?” Nothing good can be read into her exit. Nothing good at all.