Mitt, Newt, Rick and Ron are invited, but will they come?

Mitt, Newt, Rick and Ron were formally placed on the Connecticut Republican primary ballot today. Now, will any of them drop by before the polls open at 6 a.m. on April 24, a primary date that once seemed to consign Connecticut to political irrelevance this cycle?

Four years ago, a small pool of delegates did not dissuade Barack Obama, Hillary Clinton and John McCain from staging rallies here before the Connecticut primary in early February, when the candidates needed momentum as much as delegates.

Labriola, Merrill and state Rep. Tony Hwang

The primary calendar is different in 2012 as the Republican and Democratic parties largely succeeded in persuading states to stretch out the season. At the time, it appeared that late April was too late to be relevant.

“That is proving not to be the case,” said Jerry Labriola, the Republican state chairman.

That is an understatement.

With Rick Santorum winning three contests this week, GOP primaries voters are continuing to signal their unwillingness to close the deal for Mitt Romney, the consensus front-runner, at least among pundits. And 13 states don’t go to the polls until after Connecticut.

Labriola joined Secretary of the State Denise Merrill today as she announced her choices for the GOP ballot in Connecticut, a state where ballot access is determined by the secretary based her assessment of who is generally recognized as a serious candidate.

In some years, that decision is highly subjective, open to second-guessing. Not so, this year.

As expected, Merrill gave places on the ballot to Romney, Santorum, Newt Gingrich and Ron Paul. No one else had asked her for a place on the ballot before the 10 a.m. deadline, she said.

But Buddy Roemer, the former Louisiana governor and congressman asked to be placed on the GOP ballot in a letter received at 10:38 a.m. Roemer likely would have been denied access, based on his failure to win a place the previous GOP presidential debates.

State law does allow another path: Anyone can get access by gathering signatures from 1 percent of a party’s membership. In the case of Connecticut Republicans, that comes to 4,100 Republicans.

There will be no Democratic primary unless a challenger to the president gathers signatures from 7,500 Democratic voters.

On April 24, Connecticut will be one of five northeastern states — Rhode Island, New York, Pennsylvania and Delaware are the others — holding primaries in what Labriola described today as its own regional “Super Tuesday.”

“The way things are going in the Republican nominating contest so far, it could be a very significant delegate-rich day in a competitive race,” Merrill said.

If Santorum still is surging, his home state of Pennsylvania probably will be the media prize on April 24. Recent polls show the state is toss-up between Romney and Santorum, who was denied re-election to the Senate by its voters.

McCain took Connecticut four years ago, but Romney is the front-runner here this year in both polling and the amount of cash he’s raised in the state. As of Dec. 31, Romney raised $2.7 million here, with all but $100,000 coming from Fairfield County.

No other Republican raised more than $200,000.

Asked if he thought any of the candidates would campaign here, Labriola said, “I’ve certainly seen Gov. Romney in Greenwich a few times, and they were certainly in our airspace flying to New Hampshire a month ago. We are asking them to take a hard look.”