Discussing the 2010 elections for the House of Representatives with David Freddoso and Mark Hemingway earlier today, we noticed that the argument that ”the Republican Party is becoming a regional party” is nonsense — even though it’s widely repeated.

The AP, today: “With Sen. Arlen Specter’s switch to the Democrats, the Republican Party is increasingly at risk of being viewed as a mostly Southern and solidly conservative party, an identity that might take years to overcome.”

Er, no. The South amounts to 44 percent of the Republican House delegation, which means 56 percent has to come from somewhere else.

And that’s just looking at House districts. Examine these charts from CQ. McCain won 193 of the nation’s 435 congressional districts, including 49 that split their tickets to elect Democrats to the U.S. House. There are currently 178 Republicans in the House of Representatives. So a total of 227 House districts voted for either McCain, or a Republican House member, or both — in what everyone would agree was a fantastic year for Democrats.

Even if Republicans won every House seat in the South they would only have 131 seats — leaving 96 other districts across the country.

Even in their shrunken minority, Republicans hold 19 House seats in California, eight in Ohio, seven in Michigan, seven in Illinois, seven in Pennsylvania, five in New Jersey, five in Missouri, three in Minnesota, three in New York, three in Washington state, and the one seat in Delaware.

And it works in the reverse, too — Democrats actually represent more House seats in Arkansas, Tennessee, Mississippi, Virginia and North Carolina than Republicans. Neither party is as regional as conventional wisdom suggests.

What the GOP does have is a New England/New York problem, holding only three House seats in New York state.