Once, in what seems like another eon of Republican politics, George W. Bush dreamed of building a multiethnic party that would achieve dominance in a nation where the words “majority” and “minority” were losing their meaning. Mr. Bush was adamant, in the days after the terrorist attacks of 2001, that American Muslims not become the targets of public resentment, and he later pushed a plan to offer illegal immigrants a path toward citizenship.

Republicans are now taking a decidedly different approach. Last week, a group of senior Republican senators called for hearings on repealing the 14th Amendment; that’s the one that affords children born on American soil automatic citizenship. At the same time, Sarah Palin and Newt Gingrich were among those posting outraged Twitter updates over the decision to allow an Islamic center and mosque near the site of the fallen trade center towers.

These stands garnered a fair amount of publicity, and at a moment of voter insurrection, they may well yield short-term advantages for the party. History suggests, however, that the long term may be more problematic.

In both controversies, there are legitimate debates to be had. The 14th Amendment, after all, was enacted in 1868 as a means of ensuring that black Americans would be granted a full slate of rights in the era after slavery. Critics of immigration policy argue, not unreasonably, that it now has the effect of encouraging Latino immigrants to slip across the border and have children who aren’t entitled to the opportunities of citizenship. The senator who first raised the issue last week, the moderate Lindsey Graham of South Carolina, can hardly be described as an anti-immigrant crusader.