This barely used year is about to bring us something Georgia has never seen. For the first time since Republicans gained control of the state Capitol, a session of the Legislature will coincide with a statewide, GOP presidential primary that could truly matter.

On a scale of volatility, the combination falls somewhere between a torch parade through a fireworks factory and a power tool seminar with an open bar.

Shrapnel is not only possible once lawmakers convene on Monday, but likely.

Believers in traditional marriage, seeking shelter from the U.S. Supreme Court, are delighted by the prospect. But public school teachers, fearful that their pay could be tied to their performance in underfunded classrooms, could benefit as well.

Advocates of casino gambling in Georgia could be forced to work harder, with no guarantee of success. And if you’re a MARTA lobbyist, aiming for a half-penny sales tax referendum to push a rail line to the top of north Fulton County and toward Emory University, you’ll hunker down until the whole presidential thing blows past on March 1.

That’s when voters in Georgia and 13 other states join the presidential contest. Most of the ballots cast will be in the South, hence that Tuesday’s sobriquet of “the SEC primary.”

Visits by Hillary & Co. to Georgia will have little bearing on business in the Legislature, save perhaps for louder but still fruitless Democratic calls for a $15-an-hour minimum wage.

It is the Republican side of the presidential contest that is likely to turn the marbled halls of Washington Street into the selfie capital of the South. Candidates who survive the early gauntlet states – and perhaps some unaware that they didn’t – will demand face time with the Legislature’s GOP lawmakers and their campaign contribution lists.

House Speaker David Ralston said last week that all comers would be welcome. “I don’t know how many will be in the race when it gets to Georgia,” said the speaker, a fan of New Jersey Gov. Chris Christie. “I don’t think everybody that’s in now, will be. But they’ll all be invited. I’ll even welcome members of the other party.”

But parading a presidential candidate through the Capitol entails mere logistics and enough sense of protocol to determine who gets the first audience: The governor, the speaker, the lieutenant governor, or the lobbyist for the National Rifle Association?

No, in a Republican-led Legislature, the danger – i.e., unpredictability — lies in the rabble these candidates could bring with them. Armies of new GOP activists could be drawn inside the Perimeter, putting pressure on state lawmakers to support this or block that.

No Capitol debate is likely to be buffeted more by the presidential primary in Georgia than the one over the “religious liberty” bills that many conservative Christians say would give them insulation from the U.S. Supreme Court’s sanction of same-sex marriage.

The evangelist Franklin Graham has booked a Feb. 10 rally for Liberty Plaza across from the Capitol. Thousands are expected to attend. Graham, an avowed opponent of gay marriage, made news last month when he accused the Republican party of caving on a key social issue – Planned Parenthood funding.

Their campaign calendars don’t stretch that far ahead, but it is easy to imagine Donald Trump and/or Ted Cruz – the current leading candidates among Georgia Republicans – latching on to the event.

Opponents of the “religious liberty” legislation, led by LGBT activists and the business community, are aware of the potential tsunami and are acting accordingly.

For the first time, nearly 100 major businesses are publicly stepping out, forming a group called Georgia Prospers to push their contention that passage of "religious liberty" legislation would make Georgia an economic pariah.

The unified front is partly the result, no doubt, of Delta Air Lines’ experience last year. The airline was singled out for punishment by some lawmakers for its opposition to “religious liberty” legislation, and for CEO Richard Anderson’s remarks in support of a statewide tax increase to fund road and bridge repairs.

The continuing argument over gay marriage isn’t the only drama likely to be affected by the Great Convergence of the General Assembly and the GOP presidential primary.

Given that conservative Christians form the core of the Republican party in Georgia, a new and well-financed move to legalize casino gaming could also be caught in the backwash. Even if a new Atlanta Journal-Constitution poll indicates that 62 percent of registered voters support the idea, including majorities of Democrats, Republicans and independents.

After months of preparation, and a personal visit from Las Vegas mogul Sheldon Adelson to the Capitol, we have yet to see a ranking Republican declare his or her support for the proposed constitutional amendment.

At least, not one with enough clout to cut a deal with Democrats, whose votes would be essential.

Even without the overlap of a presidential primary, state lawmakers would be in a wary mood. For the second time, the state’s election calendar has set the primary election in May – only weeks after lawmakers are likely to disperse. Given Georgia’s gerrymandered districts, this is where the majority of GOP lawmakers see themselves as most vulnerable.

Throw an already warmed-up voting population into the mix, and you’re likely to get a Legislature that’s even more risk averse.

At the close of last year, Gov. Nathan Deal’s education reform commission produced a laundry list of new ventures. Topping the list was merit-based pay for teachers. Deal declared himself ready to ask lawmakers to make a “significant” step toward tying the teachers’ pay to their performance in the classroom.

Ralston, the House speaker, has already expressed his doubts about the move. The silence in the Senate has been deafening. According to that AJC poll, only 32 percent of voters surveyed approved of merit-based pay for educators.

Look for the governor to proceed slowly, piece-meal, or not at all – until 2017.

In the year of the Great Convergence, conservatism can take on all sorts of meanings.