And suppose — a real consideration for Massachusetts voters — Brown becomes a neutered outcast, while his re-election sends control of the closely divided Senate to the right-wingers. Do centrists in Massachusetts or anywhere else want tea party activist Jim DeMint, of South Carolina, controlling the powerful Senate Commerce, Science and Transportation Committee?

And with the pragmatic Republican establishment under ideological attack, its moderates may no longer feel free to be themselves. Snowe voted to create the Consumer Financial Protection Bureau, which the right opposed. But with the Maine tea party later breathing down her neck, she only voted “present” during a filibuster of the appointee to run the bureau, the unobjectionable Richard Cordray, former attorney general of Ohio.

One’s rooting for traditional Republicans to retake control of the asylum and restore a normal brand of politics. That would be very good for the country, a not-small consideration. The only side winning so far is the Democrats’.