If Bill Richardson had endorsed Barack Obama before the Texas prima-caucus, could he have helped the Illinois senator win?

Hillary Clinton won El Paso by 41,000 votes. If Richardson had campaign there and cut Obama loses to, say, 30,000 to 35,000, and also picked off a few thousands voters in small counties across west Texas, then it would have been much closer.

But would it have been enough to give Obama the Lone Star State?

Texas Democratic Electoral Map (New York Times)