The longer the campaign season goes on, the more dissatisfied Republican voters seem to be with their choice in candidates. So it’s no surprise that, even this late in the race, there remains plenty of buzz that someone perfect might still jump in — to win the nomination outright in the remaining primaries, or to build up enough steam to seize it in a contested GOP convention in Tampa.

But for all the dreaming, the reality is this: The chance of a late entry winning the Republican nomination is now exceedingly remote.

“Winning Powerball two days in a row is probably easier than any of these scenarios,” said Sean Spicer, a spokesman for the Republican National Committee.

Added Steve Schmidt, who headed up day-to-day operations for GOP nominee John McCain four years ago: “A lot of this discussion evades reality.”

The discussion of a fresh Republican face was revived on the eve of the Michigan primary, as polls showed Mitt Romney in a tough fight for a state where his family has deep ties — and that will be important in the general election this fall. If Romney cannot easily win Michigan, the thinking goes, how will he ever manage to gain momentum in the string of large battlegrounds ahead?

The delegation for New York Gov. Alfred E. Smith rallies on the floor of New York's Madison Square Garden in July 1924 during nomination proceedings for presidential candidates at the Democratic National Convention (AP/AP)

Yet it is difficult to see how anyone entering the race this late would win. The arithmetic would not work for the most direct route to the nomination, which requires racking up the requisite majority of 1,144 delegates in the remaining primaries and caucuses.

If a candidate decided to enter the race after Super Tuesday on March 6, the filing deadlines will have passed in all but seven states.

Even if that person picked up every single delegate in those remaining primaries — highly unlikely, given that only New Jersey and Utah award theirs on a statewide winner-take-all basis — the newcomer would fall way short, with fewer than 400 delegates.

“It is simply too late,” said Josh Putnam, a Davidson College professor whose blog on the GOP primary intricacies has developed a following in Republican circles. “There’s a fantasy element of this whole process.”

Well, as long as we are going there: That still leaves the possibility of taking the fight to a brokered convention, which is something many people alive today have never seen.

Among the boosters of this scenario is former Alaska Gov. Sarah Palin. “We could be looking at a brokered convention,” she recently told Fox Business Network. “Months from now, if that’s the case, all bets are off as to who it will be, willing to offer up themselves up in their name in service to their country. I would do whatever I could to help.”

Another advocate is Maine Gov. Paul LePage, who told reporters at the National Governors Association convention over the weekend: “I just believe that we ought to go to the convention and pick a fresh face.”

The four-day infomercial that passes for a modern convention is a far cry from the suspenseful events of old, with their floor fights and fistfights, their multiple rounds of balloting, their fabled backrooms reeking of cigar smoke and bourbon.

Most storied of all was the Democratic convention of 1924. With the rest of the country tuning in for the first time on radio, the proceedings in Madison Square Garden went on for 16 days and 103 ballots before John W. Davis, an obscure long shot when it all started, got the two-thirds vote then required. Davis went on to lose in a landslide to Calvin Coolidge.

The last time it took more than one round of balloting to pick a nominee was at the 1952 Democratic Convention, when Adlai Stevenson prevailed on the third ballot. And not since 1976 have both GOP candidates arrived at the convention short of a majority; that year, President Gerald Ford had to round up unpledged delegates to fend off a challenge from former California Gov. Ronald Reagan.

But a brokered convention, as political strategist Karl Rove pointed out in a recent Wall Street Journal op-ed, “needs party bosses, and today there aren’t any. In the old days, party chiefs often led delegations of regulars who took orders and depended on patronage. No longer.”

Indeed, one of the reasons that this year’s contest has had so many ups and downs is that the Republican party’s activist base has developed a revulsion to the party establishment. And those likely to attend the convention as delegates are disproportionately drawn from the far right reaches of the party — the people least likely to listen to any dictates from GOP insiders and deal brokers.

Still, the yearning for a white knight remains.

Though ex-Sen. John C. Danforth (R-Mo.) has endorsed Mitt Romney, he acknowledged in an interview that the former Massachusetts governor was not his first choice: “I was hoping Mitch Daniels would be our nominee. I think he would have been the strongest nominee we could have put forth. I still do in my fantasy — I still somehow hope something will happen that would let that happen.”

The three fantasy drafts most frequently cited — Daniels, New Jersey Gov. Chris Christie, and former Florida Gov. Jeb Bush — have given no indication that they are reconsidering their earlier decisions not to run.

And they would have even greater pause as they considered the experience of others, such as Texas Gov. Rick Perry, who seemed ideal in the wings, but wilted once they got into the spotlight. There is also the challenge of marshaling the resources and organization to compete with what the four current candidates have spent more than a year building.

Even though Republicans are far from enchanted with the current crop of candidates, they have misgivings about stretching the nominating contest into the convention.

In a mid-February poll conducted by Gallup, 66 percent of Republicans and Republican-leaning independents said they would prefer to see one of the four who are currently running pick up enough delegates to cinch the nomination before the party convenes in Tampa.

Republicans may not think any of them is ideal — in fact, 55 percent of those surveyed told Gallup they wish someone else were running — but they are coming around to the realization that this field is all they’ve got.

Researcher Lucy Shackelford and staff writer Rosalind S. Helderman contributed to this report.