Romney leads Super Tuesday race after Massachusetts win.

National Post - Mitt Romney extended his delegate lead in the Republican presidential race with victories in five Super Tuesday states, giving him a measured dose of momentum as he tries to tighten his grip on the GOP nomination.

But in a continued sign of strong opposition to Romney in the GOP’s conservative base, he was unable to stop Rick Santorum and Newt Gingrich from claiming Super Tuesday successes of their own.

Romney was triumphant in Massachusetts, where he served as governor, and also coasted to wins in Virginia, Vermont and Idaho.

His most important projected victory, however, came in the general election battleground of Ohio.

“I’m going to get this nomination,” Romney assured supporters in Boston.

Santorum, the former Pennsylvania senator, won in Tennessee, Oklahoma and North Dakota. All three states are strongholds for evangelicals and Tea Party activists.

Gingrich, meantime, won a decisive victory in Georgia.

The Ohio primary, as expected, was the Super Tuesday nail biter.

With 96% of Ohio precincts reporting, Romney held a lead over Santorum of about 12,000 votes. Romney had trailed through much of the evening but pulled ahead on the strength of his support in Cleveland and Cincinnati.

No matter the final count, Romney was expected to win the lion’s share of Ohio’s 66 delegates because Santorum failed to properly file paperwork for delegates in parts of the state.

But Romney’s difficulties in Ohio — where he won by narrow margin despite outspending Santorum by a wide margin — are likely to further doubts about his electability and his appeal particularly with blue-collar Republicans.