Mitt Romney’s across-the-board victory in the Florida Republican presidential primary on Tuesday night serves as a direct rebuttal to the criticism that he simply isn’t conservative enough to be the party’s nominee and leaves his remaining rivals with few obvious next steps as the nomination fight moves to Nevada next month.

View Photo Gallery: Voters in the Sunshine State — more than in the first three states’ contests combined — cast their ballots Tuesday in the Republican presidential primary.

Exit polling reveals that Florida’s primary electorate on Tuesday was more conservative than four years prior when Sen. John McCain (Ariz.) won the state and wrapped up the nomination.

Eight in ten Florida primary voters identified themselves as Republicans and Romney beat Gingrich among that group 48 percent to 34 percent. (Florida is the first vote of 2012 that is limited to only registered Republicans.) Two in three Florida voters said they supported the Tea Party movement.

Florida’s recent past also suggests it could have been friendly territory for a conservative insurgent challenging a more centrist Republican. In 2010, now Sen. Marco Rubio surged past then Gov. Charlie Crist, forcing Crist out of the Republican primary due to a rapid erosion in his support.

Given the exit polling and recent Florida political history, former House Speaker Newt Gingrich, Romney’s main rival for the Republican nod, could struggle to make a convincing case — as he has attempted to do in recent days — that Romney cannot win a one-on-one fight against a more conservatively-aligned candidate.

Polling conducted in recent days also complicate Gingrich’s argument. In both NBC-Wall Street Journal and Washington Post-ABC polling, it’s Romney, not Gingrich who would benefit if former Pennsylvania senator Rick Santorum, a conservative favorite, decided to drop from the race. (Santorum has pledged to continue on in the contest despite a less than rousing finish in Florida tonight.)

Romney’s clear victory also offers few obvious outs for his rivals, most notably Gingrich.

The political parapet to which Gingrich will likely cling is that Romney’s victory was due in large part to the heavy spending by he and his affiliated super PAC, expenditures that dwarfed the dollars dropped by the former House Speaker.

As of Jan. 29, Romney’s campaign and Restore Our Future, the affiliated Romney super PAC, had spent $15.6 million on ads in Florida as compared to $3.29 million disbursed by Gingrich’s campaign and the pro-Gingrich Winning Our Future super PAC.

And so, Gingrich has a point. But only to a point.

The presidential primary race will now move from places like Iowa, New Hampshire and South Carolina — all small(ish) states where retail politics is the coin of the realm — into states that, like Florida, have large populations, diverse electorates and where television is king. (Two royal references in one sentence!) Think Ohio, Michigan, Arizona and so on and so forth.

That means that unless Gingrich can begin to raise money at a much faster clip or his super PAC can match the spending of Romney’s super PAC spending, he’s likely to find himself fighting the same, losing fight in the states and weeks to come.

Florida’s primary result also complicates the efforts of Gingrich to paint the race as a choice between the establishment’s choice and the peoples’ choice.

While Romney and Gingrich both racked up their fair share of endorsements from Florida elected officials, the major players like former Florida governor Jeb Bush and Florida Sen. Marco Rubio stayed on the sidelines.

Without Bush and Rubio trying to throw their weight around, Romney was, largely, forced to win Florida on his own. And win it, he did.

(A note on endorsements: Romney had the support of South Carolina Gov. Nikki Haley as he went down in flames in the Palmetto State, a result that makes clear the relative limitations of endorsements of any sort.)

The silver lining for Gingrich, Santorum and even Texas Rep. Ron Paul is that the presidential race to date has been predictable only in its unpredictableness. (That may or may not be a word.)

The nomination was all-but-handed to Romney following his victory in New Hampshire on Jan. 10 but 11 days later Gingrich’s massive South Carolina win raised serious questions about whether the former Massachusetts governor was even the favorite for the nod any longer.

But, make no mistake: Romney’s victory tonight is total. Gingrich led the Florida primary in the days following South Carolina’s vote but watched that lead ebb away amid middling debate performances, an avalanche of negative ads and his own self-inflicted wounds (permanent moon colonies, anyone?)

Romney’s Florida victory re-establishes him as the clear favorite for the Republican nomination. It also puts the onus on Gingrich, Santorum and Paul to find a convincing argument as to why — and how — they can beat him.