After Saturday’s South Carolina primary shook up the Republican presidential race, the four major candidates matched up on Monday in the first of two debates in Florida, which votes next on January 31.

A new twist on “Newt Romney”: Newt Gingrich got a taste of the one-on-one debate he’s proposed having with Mitt Romney Monday night, when the former Massachusetts governor launched an unrelenting attack against Gingrich and kept at it for much of the evening.

Hitting the mute button: At first this seemed like a modest change to the debate’s rules, but it ended up having a significant effect. In a debate season where audiences have lustily cheered for their favorite candidates or in support of hard-line conservative principles, the absence of feedback was notable.

Trying to shoulder into a two-man race: Rick Santorum has worked hard over the last several weeks to remind people that this isn’t a two-man race and has consistently blamed the media for prematurely narrowing the field. He repeated that argument on Monday but had trouble making it stick.

Practice makes perfect?: After a week of faltering answers, Mitt Romney managed to give a fluid response to questions about his tax returns — just one day before he was scheduled to release them.

All politics is local: After primaries in three states that will play relatively minor roles in the 2012 general election, almost a third of Monday’s debate focused on issues important to Florida, a swing state in November.

For one long portion of the debate, the questions ranged from the potential effects of another oil spill on the Sunshine State’s vital tourism industry to the future of federal subsidies for Florida’s sugar industry. Even the long-forgotten Terry Schiavo case came up.

More here.