Jonathan Alter writes that the Republican Party has once again taken its support for a wedge issue too far, in his column, “Republicans Are Unprotected On Contraception:”

During the 1928 presidential campaign, nutty right-wing Protestants claimed that Al Smith, the first Catholic nominated for president by a major party, was planning to extend New York’s Holland Tunnel all the way to the Vatican.

Today’s tunnel would run from the Vatican to a suburban Pentecostal megachurch.

We learned this week that U.S. Catholics support President Barack Obama’s Feb. 10 compromise on contraception in almost identical numbers to the population as a whole. Many of those sticking with the Catholic bishops in opposition are evangelical Protestants.

Historians are rubbing their eyes in wonder that the spiritual and political descendants of Protestants who founded the Know Nothing Party in the 1850s on anti-Papist ideas — who hassled not just Al Smith but also John F. Kennedy for supposed ties to Rome — are now embracing Catholics. Rick Santorum was recently greeted at Oral Roberts University by an enthusiastic crowd of 4,000.

Yes, politics makes strange bedfellows, and in this case, the Republicans, by throwing in their lot with the bishops, are using no protection. Like the controversy over the Susan G. Komen for the Cure foundation withdrawing support from Planned Parenthood over its provision of abortion services, this struggle leaves Republicans politically exposed.