Just as an interesting sidenote, here's the current delegate count (roughly...due to all the non-binding caucuses and arcane bullshit, no one can be sure of the actual count yet):
Romney: 173
Santorum: 74
Paul: 37
Gingrich: 33
Now here's what the count would be if the primaries had all been the "traditional" winner-take-all binding primaries:
Romney: 245
Santorum: 104
Gingrich: 25
Paul: 0
This is why in past seasons, the race is typically down to 2-3 people by the time shit gets real. The mass expansion of proportional primaries and caucuses has been a big impediment to one person racking up a bunch of tight victories early on and getting a commanding lead in delegates. Or in other words, this kind of clusterf**k isn't going away. It's the new normal. Which makes me wonder if a lot more people will be running in future Presidential contests, given that a theoretical non-starter like Ron Paul is still in 3rd place (and continues to focus on subverting the caucus process to milk delegates out of states where he's not even getting 20% of the popular vote). You don't need to be the front-runner (in fact it's much easier if you're not), you just need consistent 2nd and 3rd place wins to rack up those delegates. Margin of win is now as important as the win itself. And because every single race tomorrow is some flavor of proportional, this won't be the knockout punch for any of the candidates.
Initially, it was looking like Santorum might actually take the majority of the races. Now it's looking more even but it's going to come down to margin. Romney will run away with Massachusetts, but it's still proportional. Santorum is looking to run away with Oklahoma, and OK is one of those Proportional++ states I referenced several pages back wherein if he wins an outright majority (a distinct possibility...he's polling at 43% as of a few weeks ago), then it becomes winner-take-all. That's 43 delegates which takes a pretty big bite out of the gap between them.
OH and TN are also Proportional++ states, but those look like they'll be very close races, so they're basically a 50/50 split. Where Santorum might have the edge in those races is that the delegates are awarded based on districts won. Romney's support tends to be geographically concentrated, so he'll win a relatively small number of districts clumped in urban areas. Santorum will likely win large swathes of the rural state, which should translate into more districts.
Virginia is an odd bird, and potentially the biggest win of the night (and biggest controversy) for Romney. As I understand it, it's a semi-open primary and winners are awarded delegates based on districts won with a bonus set awarded to the statewide winner. BUT...if one candidate gets a majority, the whole thing becomes winner-take-all. Santorum and Gingrich are not even on the ballot in Virginia. As a result, Romney is polling near 70% in Virginia. Which could wind up giving him all 49 delegates outright -- a small chunk compared to the grand total he needs to win, but it could very well be the margin of win by the end of this thing. Especially crucial if Santorum wins OK outright, as it nullifies his big gain there. But controversial because of the arcane rules and the fact that the Virginia state GOP apparently
changed the rules to get on the ballot as late as November 2011, which caused Gingrich's application to get tossed and caused Rick Santorum to not even try to get on the ballot (to be fair, I honestly don't think he thought he'd still be in this thing by this point).
To sum up the article linked above, there was a lawsuit regarding how the signatures to file should be verified. End result was that the state GOP bumped up their "automatic threshold" from 10,000 to 15,000. Meaning that if you present 15,000 signatures of people ostensibly wanting you to run for President,
they don't get validated and you're on the ballot. Less than 15,000 and the signatures have to be validated. Too many get thrown out (as happened for Rick Perry and Newt Gingrich) and drop you below a certain threshhold (which I can't seem to find), and you're off the list. Romney was the only one to submit 15,000 signatures, suggesting that they didn't do a good job of getting the word out about the rule change. Expect to see Team Gingrich and Team Paul file suit and call on Team Romney to allow their list of signatures to be validated. To his credit, even though Paul's submission was below the 15,000 mark it passed validation. It does kind of make me go WTF that these other candidates submitted *that many* fake and/or invalid signatures. Is this just a normal practice?