Mitt Romney has won a majority of the delegates available on Super Tuesday , even as he and Rick Santorum remain deadlocked in Ohio.

So far, ABC News estimates that Romney has won 213 delegates. Rick Santorum (84) and Newt Gingrich (74) follow, with Ron Paul (22) tailing. The 10 Super Tuesday states will send a combined 437 delegates to the Republican National Convention in Tampa, Fla., in August, though not all of those delegates will be awarded to candidates tonight.

ABC News projects Romney to have won Massachusetts, Virginia, Vermont, Idaho, and Alaska. He has collected 38 delegates from Massachusetts, out of 41 total delegates from that state; all of Idaho's 32 delegates; 43 from Virginia, out of 49 total; nine from Vermont, out of 17 total; and eight from Alaska, out of 27 total. He also won 13 in Oklahoma, 10 in Tennessee, 14 in Georgia, and 35 in Ohio. Some of those counts could climb as more votes come in.

Meantime, Gingrich kept his campaign alive with a swift decision in his home state of Georgia , good for 48 delegates, out of 76 total in the state available. The former speaker of the house will be getting Secret Service protection beginning tomorrow.

ABC News also projects that Santorum has won Oklahoma, Tennessee, and North Dakota. So far, Santorum has won 14 from Oklahoma; he has taken 25 delegates from Tennessee, out of the 58 that state has on offer tonight. Santorum won the backing of an estimated 11 unbound delegates from North Dakota, out of 28 total from that state, according to ABC's projection.

There is no projected decision yet for Ohio, where Romney (35) holds the edge over Santorum (25) in the state's 66 total delegates.

Those numbers will change as more votes are tallied in Ohio.

Judging delegate expectations is a difficult business.

By rule, each state is allowed to devise its own rules, and all those rules differ from one another in subtle or radical ways. To accurately predict who will win which delegates where, one has to know how each congressional district will vote, whether certain candidates will meet 15 percent or 20 percent thresholds in districts and states, and whether some states will become winner-take-all if enough votes go to the leader. Not all of the 437 Super Tuesday delegates will be "awarded," as most states will send three party officials to the national convention as unbound delegates. The nuances go on.

If no candidate reaches 1,144 delegates by August, Republicans will decide their nominee on the floor of their national convention in Tampa, Fla. With Romney in a commanding lead, a big question surrounding delegates is: Can Romney's competitors perform well enough, and stay in the race long enough, to keep him from reaching 1,144 and force a convention fight?