As it rose to power in the late 1850s, the Republican Party absorbed the anti-Catholic populists of the American Party who live in historical memory as the Know-Nothings. So called because they denied all knowledge of what their party stood for, the Know-Nothings contributed a nativist gene to the GOP that it has never managed to knock out.

In the early days, Catholics and Jews were the principal suspect classes of outsiders. The problem, especially when it came to Catholics, was that there were just so darn many of them by the end of the 19th century that it didn’t pay to indulge (at least publicly) in anti-Catholic bigotry. At the end of the 1884 presidential campaign, a Presbyterian preacher introduced GOP nominee James G. Blaine to a crowd of Protestant clergy with the words, “We are Republicans, and I don’t propose to leave our party and identify ourselves with the party whose antecedents have been rum, Romanism, and rebellion”–thereby costing Blaine the election.

In recent years, the wise guys in the Republican Party have cottoned to the fact that the U.S. of A. has become a good deal more Latino than it used to be, and that it might not be such a good idea for the future of the GOP if it embraced (at least publicly) such anti-Latino-immigrant laws as Arizona passed a few months ago. Why not find a less politically potent body of Americans on which to vent one’s nativist animosity? 

I give you: The Muslims. Unlike the Latinos, who are pushing toward 20 percent of the American population, they constitute less than one percent. And the largest portion of them are African-Americans who would never vote Republican anyway. But how to change the nativist narrative in time for November’s mid-term elections?

The Ground Zero Mosque, of course. Talk about godsends. In May, when the story emerged, the ratio of newspaper, broadcast, and blog coverage of the Arizona law to the proposed Islamic Center in Manhattan was 20:1. Last month, it was 10:1. So far this month, it’s been running at 1.3:1. That’s according to Lexis-Nexis Academic word searches of Arizona+law+immigration+Brewer and Ground Zero+mosque+protest. Add coverage of other anti-Muslim protests around the country and the ratio turns the other way.

Ugly it may be, but you’ve got got to hand it to Palin, Gingrich, and Co. They know what they’re doing.