The rat-a-tat-tat between the Mitt Romney presidential campaign and the Susan B. Anthony List anti-abortion group over the weekend revealed an unpleasant parochialism among these sorts of activist groups. Romney didn’t sign its pledge so the grass roots descend en masse, and his opponent Rick Santorum (whose support of Tom Ridge for secretary of homeland security would not have met the pledge’s requirements) screeches. This is lunacy.

Romney and the other candidates are being used as fundraising tools for whipping up the base. Whoever doesn’t hop to the tune of these groups had better watch out.Mailers go out, funds are raised and the accusations of squishiness fly. Whether or not you think Romney is solid on abortion, his willingness to sign this or that pledge is irrelevant. If this gamesmanship — send an extreme and nebulous pledge and vilify whoever doesn’t sign it — is all these groups have to offer, maybe they need to rethink their mission. And the scramble to best all others in the “purity” game in not one that redounds to the Republican Party’s benefit.

One final point: Billy Valentine, SBA’s deputy director who fielded questions all day Saturday, was a visible and bitter anti-Romney critic and student activist in 2008. In a voicemail message, his boss acknowledged that Valentine had done “some anti-Romney campaign things” before she hired him.

Judge for yourself what is going on here. But don’t confuse a candidate’s position on any issue with his willingness to sign a pledge. Real presidential leadership isn’t demonstrated by succumbing to the entreaties of this or that group whose allegiances and decision-making process are not transparent. My hunch is these groups’ ability to sway voters in this manner is diminishing, just as the power of endorsement s by other politicians is fading. That, I think, is all to the good.