In responding to its popular-vote loss in the Michigan primary last Tuesday, Rick Santorum’s campaign argued that the result amounted to a tie since the former Pennsylvania senator and former Massachusetts governor Mitt Romney were both slated to win 15 delegates.

(Later, one delegate was controversially shifted to Romney, who wound up edging Santorum 16 to 14.)

That argument could pretty easily backfire on Super Tuesday tomorrow.

As Romney’s campaign pointed out this weekend, Santorum’s campaign is not on the ballot in Virginia and failed to file for as many as 18 of the available delegates in Ohio.

It all adds up to a situation in which Santorum could have a very good day in terms of raw vote but still come away with significantly fewer delegates than Romney.

In Ohio and Virginia alone, Santorum is ceding upwards of 64 delegates — about 15 percent of the more than 400 delegates at stake on Super Tuesday.

What’s more, Romney is virtually guaranteed wins in Virginia — where only he and Texas Rep. Ron Paul are on the ballot — as well as Vermont and his home state of Massachusetts.

Romney is likely to win all 46 delegates at stake Tuesday in Virginia, because that state awards its delegates (both statewide delegates and congressional district delegates) on a winner-take-all basis if a candidate wins a majority of the vote. And it’s very likely that Romney will do just that; a poll released this weekend put him more than 40 points ahead of Paul in the Commonwealth.

Assuming Romney wins Massachusetts, Vermont and Virginia handily, as he should even on a bad night, that would likely give him somewhere between a 60-delegate and an 80-delegate head start over the rest of the field before we even look at the other seven states set to vote.

Where does the delegate hunt go after that? There are three basic scenarios (reflected in the video above):

1. A Romney romp: If Romney were to win the rest of the states in a romp, taking all 10 on Tuesday or almost all of them, he could expand his delegate lead by upwards of 150 or 200 delegates.

2. The candidates split the map: Romney and Santorum split the rest of the states. Maybe Romney wins Ohio and Idaho, Santorum wins Alaska, North Dakota, Tennessee and Oklahoma, and Newt Gingrich wins Georgia. Even though Santorum has won more of the key states, he gives away so many delegates in Massachusetts, Ohio, Vermont and Virginia that he winds up losing the delegate race on Super Tuesday by 80 or 90 delegates.

In fact, even if Santorum also wins Ohio — taking five of the 10 Super Tuesday states — he would still likely lose the delegate count on Super Tuesday, as long as Romney is still competitive in those states and wins a fair amount of delegates.

3. A Santorum sweep: Let’s say, aside from Massachusetts, Vermont and Virginia, that Santorum wins every state handily — with around 50 percent of the vote. Even in this highly unlikely scenario, we calculate Santorum would only net about 40 or 50 delegates.

And given that Romney already leads by more than 100 delegates, that wouldn’t even put a big dent in Santorum’s deficit.

In other words, this is precisely the wrong time for the Santorum campaign to start talking about delegates.

The campaign would be much better served arguing that this race is still about momentum, because it’s much more likely that Santorum comes away from Super Tuesday with momentum from wins in states like Ohio, Oklahoma and Tennessee than it is that he would come away with more delegates.