Kate O’Beirne’s piece in The Daily News about Rudy Giuliani and the Catholic vote is right on target.

The Christie Todd Whitman Republicans have long promulgated the myth that the GOP can expand its appeal by dropping the social issues. The truth, as Kate points out, is the opposite. The Republican Party expands its appeal through social conservatism. Not only does social conservatism help keep the South–where there are many evangelical Christian voters–solidly Republican (this was one of Zell Miller’s arguments for why national Democrats cannot win in that region), but it also helps the GOP win Catholic voters in Midwestern swing states that are likely to determine the outcome of the 2008 election–just as they determined the outcome of the 2004 election.

In 2004, as Kate points out, George Bush beat the socially liberal Catholic John Kerry among Catholic voters nationwide.

In the 2004 network exit poll–which over-sampled liberals and thus predicted Kerry would do better than he actually did–22% said “moral values” mattered most in deciding their vote for president. That beat the economy/jobs, which had 20%; terrorism, which had 19%; and Iraq, which had 15%.

Iraq is likely to move up in voter importance in 2008, and not to the advantage of Republicans. In that environment, can the GOP afford to throw away its advantage on social issues?

In the key swing state of Ohio, whose electoral votes determined the outcome of the 2004 election, Bush had an added advantage: Thanks to Ken Blackwell, there was a marriage amendment on the ballot that won 62% and helped turn out socially conservative voters. Nonetheless, in that rust-belt state, the economy was more important with voters than it was nationwide. Twenty-four percent of Ohio voters told the exit poll the economy was the most important issue deciding their vote, while 23% said it was moral values. Kerry won 83% of Ohio’s economy voters, and Bush won 85% of its moral-values voters. Significantly, Catholic voters made up 26% of the Ohio electorate, and Bush beat Kerry among these voters by 11 points.

Bottom line question: If the GOP runs a candidate such as Rudy Giuliani, who mirrors the Democratic candidate’s liberal positions on key social issues, and who will not benefit from the presence of a marriage amendment on the ballot, does the GOP increase or decrease its chances of winning Ohio?

Running against a senator who just won a landslide reelection in New York, Giuliani is far more likely to paint Ohio blue than his home state red.