RALEIGH – It’s Pennsylvania primary day. I’m sticking to my guns – it won’t matter much.

Some weeks ago, I wrote that May 6 had become the most important date on the Democratic primary calendar. North Carolina, and to a lesser extent Indiana, will determine the fate of Barack Obama and Hillary Clinton far more than today’s vote will.

Pennsylvania was always going to be congenial territory for the Clinton campaign. Parts of the state vote more or less like Ohio, where she did well, and its primary is closed to independents, a key Obama constituency. The state is full of older, downscale Clinton voters who were going to be hard sells for the Obama campaign no matter what. He outspent her on television by a three-to-one margin and made up some ground, but I don’t think it will prove to be enough. That big quaff of the bitters he took in San Francisco slowed his momentum.

Some of the pundits and campaign mouthpieces have been trying to set Clinton’s expectations high enough to transform a solid Pennsylvania win into a loss. As usual, I don’t believe that the Obama team (which includes many of those fawning TV and newspaper commentators, with Great Society dreams dancing in their heads) will prevail in the expectations game. The Clintons are better at it. Sure, if Pennsylvania proves to be a true squeaker, her longshot candidacy will take a major hit. But a solid margin for her, even if it’s less than a double-digit blowout, will net Clinton a large bloc of votes – reducing her popular-vote deficit, which is now the key statistic in the Democratic race, particularly with her victory margin in the Florida primary factored in.

As for North Carolina, I’ll also stick to my prediction: its primary could be decisive. If Obama maintains his substantial lead here and blows her out, that could make it mathematically impossible for her to catch up in the popular vote in subsequent, smaller states. And if, somehow, Clinton were to come from behind and eke out a victory here, it would knock the Obama campaign for a loop and cause a major crisis of confidence.

The in-between outcome in North Carolina – an Obama win but an impressive, high-40s showing by Clinton – is perhaps more plausible, and would be somewhat less dramatic. It would keep her popular-vote dreams alive but give Obama his first big-state win after a long spring drought.

Of course, all of my speculations would be moot if Clinton falls to Obama tonight in Pennsylvania. Guess we’ll find out soon enough.

Hood is president of the John Locke Foundation.