Republican presidential hopeful Mitt Romney walks towards his bus after a campaign rally in Florence, S.C. on Jan. 17, 2012.

In a spirited press conference just now in Florence, S.C., Mitt Romney made news on several fronts. Here are the highlights:

- Romney said he "probably" pays only about 15 percent in federal taxes because most of his earnings come from capital gains, which is taxed at a lower rate than traditional income. This means the super wealthy Romney pays a significantly lower tax rate than most middle income Americans.

- He sharpened his answer on releasing his tax return in April because, he says, that is the precedent and it will enable him to release the current year return, not earlier years.

- In other words: Romney plans to release only his 2011 return and will do it after the key primaries are over.

- By the way, President Obama released his tax returns in March 2008, well before he clinched the Democratic nomination. And George W. Bush, as governor of Texas, released his returns before he was even a candidate.

- Romney explained his claim of creating more than 100,000 jobs at Bain: Add up ALL the jobs now at the four largest companies Bain helped start (Staples, etc), which is 120,000, and subtract the 10,000 jobs lost at Bain companies that went under and you have, voila, more than 100,000 jobs.

- He came out definitively against private accounts for Social Security (Newt Gingrich's plan and something favored by many conservatives) because they would leave a hole in the Social Security trust fund (an argument often made by Democrats).

- He hammered Rick Santorum again for favoring voting rights for felons and said his Super PAC ad on that is accurate.

- A day after he seemingly criticized Super PACs, today he defended them and said he encourages those that supported him. It is the law that is the problem, not the Super PACs, he said.

- He recited a litany of subjects on which he disagrees with both Gingrich and Santorum.