David Frum, Rush Limbaugh, David Keene and others have expressed the fear that if the Republican candidate and platform in 2008 aren’t tough on immigration, there could be a split in the party. More evidence of this in a recent column from Paul Weyrich, where he goes farther than I’ve seen him go before: “As conservatives, we need to make it clear that we will not vote for any candidate who refuses to close our borders to illegal immigration and cut back on legal immigration, at least until we can acculturate the immigrants we already have. More, we will actively support candidates, including in primaries, who promise to take the actions necessary to control our borders.”