Ronald Reagan lost the 1976 GOP nomination to Gerald Ford, but landed the final speaking slot .

CNN LIVE: Tune in tonight at 6 p.m. ET for live coverage of the Arizona and Michigan primaries and follow real-time results on CNNPolitics.com, on the CNN apps and on the CNN mobile website. Follow CNN Politics on Facebook and on Twitter at #cnnelections.

Story highlights

Today's primary in Michigan could upend the race for the nomination if Romney loses

Brokered convention possible if no candidate has enough delegates by convention

Unlikely but plausible, say political insiders, if no front runner emerges

Washington CNN  — 

Two months into the Republican presidential nominating process, many thought that one candidate might have it sewn up by now.

The scenario was simple: An easy win in the first four states, coupled with big support from party leaders, fat bank accounts chock-full of campaign cash and a slew of rival candidates who would have likely folded by now, would virtually guarantee a smooth path to the GOP convention in August and a quick nomination on the first ballot.

So much for conventional wisdom.

The GOP front-runner status has changed hands no less than a half-dozen times so far. Upstart Rick Santorum has been surging nationally on a platform of conservative social issues, the latest “non-Romney” to move up. Newt Gingrich – who was leading at the beginning of the year, won in South Carolina but has faded since – won’t go away. Ron Paul, drawing some of the most passionate followers online and at campaign rallies, appears to be in it for the long haul. And Mitt Romney, once seen by some as a shoo-in for the nomination, is feverishly draining his campaign accounts trying to beat back rivals with aggressive, and often negative, TV ads. Still, he is not even close to closing the deal with voters.

On the day of critical primaries in Arizona and Michigan, and a week before the Super Tuesday contests in which 10 states will cast ballots for their preference for nominee, the race for the Republican nomination is far from settled.

More than delegates at stake in Arizona, Michigan primaries

Some speculate that no candidate will secure the necessary 1,144 pledged delegates needed to nail down the nomination before the GOP convention begins on August 27. That could mean chaos for Republicans.

Most observers are calling Michigan a “do or die” state for Romney. Michigan is the state where he was born, the state where his father, George Romney, was governor, the state he easily won in 2008 and the state he must win next week in order to restart his stalled momentum.

But rival Santorum is in a virtual dead heat with Romney in Michigan, having racked up impressive victories earlier in Iowa, Colorado, Missouri and Minnesota. If he were to upset Romney in Michigan, the entire nomination process could again be in turmoil leading into Super Tuesday next week, making a battle at the Tampa convention even more likely.

What is a brokered convention?

So, could all this lead to confusion in Tampa and a convention free-for-all? Could a brokered convention – where no single candidate has enough delegates to win the nomination outright and a fight on the floor of the convention occurs – really happen?

Last week, former candidate turned Newt Gingrich-supporter Texas Gov. Rick Perry, told CNN that a brokered convention is a real possibility, but he doesn’t see that as a problem.

“I think the Republican primary voters and the American people are just interested in solutions for what face this country,” Perry said. “The process of how we get there and the process of how we choose this person is substantially less of concern to the American people.”

GOP’s worst nightmare – a contested convention

But New Jersey Gov. Chris Christie, a Romney-supporter – and the subject of whispers that he might make a late entrance into the race (speculation that he has strongly rejected) – said he doubts the race will go all the way to the convention floor.

“That’s stuff that folks in the media and in political punditry like to talk about because it’s like their dream come true, that we’d actually have indecision going into a convention,” he said the New Jersey governor at a press conference last week. “Hasn’t happened in the Republican Party since Wendell Willkie, I don’t think it’s going to be happening in 2012.”

The fight of ’76

The last time a Republican front runner failed to secure enough delegates to walk into a convention as the presumptive nominee was in 1976. Gerald Ford, who assumed the presidency after Richard Nixon resigned, was in a heated race with former California Gov. Ronald Reagan, but just couldn’t close the deal.

Going into the ’76 convention in Kansas City, Ford had already won more delegates and had won more of the popular vote than Reagan, but did not have the necessary delegates to win the nomination outright.

So Reagan, the Hollywood conservative who had been billing himself as the “Washington outsider,” launched an aggressive move during the first days of the convention to convince unpledged delegates to vote for him and committed delegates to switch allegiances. He attacked Ford on his tempered moves with the then-Soviet Union, and painted his policy of détente as a sign of weakness.

But Ford, the former vice president, member of Congress from Michigan and consummate party insider used his strong party connections to beat back a floor fight and win the nomination with 1,187 delegates (53%) to 1,070 (47%) for Reagan.

Ford later gave Reagan the last speaking slot at the convention, and during his remarks, the former actor clearly out-shined the nominee with a famous speech that positioned him well to get the nomination four years later.

The Republican pattern

Former George W. Bush press secretary and CNN contributor Ari Fleischer said that picking the loser from the previous campaign to become the next GOP candidate is consistent road map.

“Just look at the history of the Republican Party. The person who ran in the previous cycle and lost eventually becomes the nominee next time around,” said Fleischer. “That is the pattern of the modern-day Republican Party.”

Just look at their history:

1960: Nixon won the nomination but lost the election to John F. Kennedy.
1968: Nixon became the nominee again (his main GOP opponent was Michigan Gov. George Romney), then defeated Hubert Humphrey to be elected president.

1976: Reagan lost the nomination to Ford; Jimmy Carter was elected president.
1980: Reagan won the nomination, then defeated Carter to be elected president.

1980: George H.W. Bush lost the nomination to Reagan; Reagan was elected president.
1988: The elder Bush won the nomination (beating Bob Dole), then defeated Michael Dukakis to be elected president.
1996: Dole won the nomination, but lost the election to Bill Clinton.

2000: John McCain lost the nomination to George W. Bush; Bush was elected president
2008: McCain won the nomination (defeating Romney), but lost the election to Barack Obama.

Still, a Romney victory in 2012 is far from certain right now. In the most recent Gallup national tracking poll, Romney is in a statistical dead heat with Santorum 31% to 29%. With 59 delegates at stake today and another 437 up for grabs on Super Tuesday, the race could change in an instant.

The race for delegates

Romney is the current leader in delegates, having racked up victories in New Hampshire, Florida, Maine and Nevada. According to the latest CNN delegate estimate, Romney has likely earned 127 delegates, Gingrich has 38, Santorum has 37 and Paul has 27.

But several of those states – Iowa, New Hampshire, Colorado and Minnesota – have not yet awarded any actual delegates. They will be allocated at the state and local level later this year. So, technically, those delegates could be in play.

And Florida, South Carolina and Nevada have been penalized by the Republican National Committee for holding their contests early, and will likely lose half of their delegates to the convention. But that penalty – and several states’ winner-take-all status – could be a point of contention during a GOP rules committee battle, a fight that could shift the balance before the convention.

If it comes to that, the real battleground would be a fight to secure the delegates themselves. Even if a candidate has a majority of delegates before the convention, but not enough to become the presumptive nominee, insiders say the most likely scenario would be that party leaders would work to cut a deal between the top candidates well before the convention – perhaps quietly offering a VP slot or cabinet position in exchange for delegates – avoiding bad blood during the convention itself.

With filing deadlines in many states already past, it is nearly mathematically impossible for a new candidate to enter the race now and rack up the 1,144 delegates needed to win the nomination outright.

A surprise candidate?

The most plausible – but still improbable – scenario would be if an individual parachuted into the race in late spring or early summer, with the expressed intention to fight for the nomination in Tampa on a second ballot, after pledged delegates are released from their obligations.

But that, said Fleisher, is “highly unlikely.”

GOP knight in shining armor isn’t going to happen

In fact, Fleischer said the only names with enough national presence to compete at this point – Jeb Bush, Mitch Daniels, Paul Ryan and Chris Christie – have all made it clear they’re not interested. “I see no scenario where any of them get in,” he said.

“But we’ll have to wait and see. If, by Super Tuesday, no strong front runner has emerged, then we could be looking at something different, very different.”