As the government shutdown laid bare, Republicans have an all-out civil war on their hands, one that is pitting establishment types against Tea Party insurgents.

On Tuesday, the battle shifted to Alabama, where GOP voters cast ballots in the runoff election to choose the party's nominee for the state's 1st Congressional District. Though the race hardly has the star power of, say, New Jersey's gubernatorial contest, it could very well offer the most intriguing glimpse of any of Tuesday's races into the future of the Republican Party.

The race, between former state Senator Bradley Byrne and Tea Party-aligned activist Dean Young, presents the Alabama GOP with a choice between two deeply conservative candidates. Both are outspoken Christians and social conservatives who oppose the deal that ended the government shutdown.

Of the two, though, Young's populist Tea Party streak places him further to the right. Byrne is an established politician endorsed by the Chamber of Commerce who talks about solving problems through cooperation; Young is a polemic firebrand who thinks President Obama was born in Kenya and describes his own supporters as "pitchfork people."

So although they share common political beliefs, they have very different ideas about what the modern GOP should look like. Young has turned the contest into a referendum on the party at large, labeling Byrne a "country club Republican" and suggesting his opponent would be more of the same in Washington. Byrne, meanwhile, has hammered Byrne as a crank with no real policies.

"If you’re looking for somebody who's just going to go up there and fight, he's your guy," Byrne said at a recent event. "If you’re searching for somebody who's going to up there and fight and be effective, I'm your guy."

In that way, the election has become not a simple choice between two candidates, but rather a choice about "what tactics Republican activists think will be most successful as the next budget showdown looms," says the Daily Beast's Ben Jacobs. It's the same choice congressional Republicans are facing between the "suicide" and "surrender" caucuses, as they've been derisively referred to by their respective opponents.

It could also set a pattern for future elections, with an insurgent raising money based on resentment toward the Republican Party itself. Michael Gerson at The Washington Post explained the troubling implications of such a development:

The result is a paradox. Over the past few decades, Republican members of Congress have become more reliably conservative (as their Democratic colleagues, to a lesser extent, have become more liberal). Liberal Republicanism has essentially ceased to exist. This means that tea party conservatives are revolting against a more uniformly conservative party. The RINOs they hunt are actually an endangered species. [The Washington Post]

Still sore from the government shutdown, business interests are stepping in, saying they would boost business-friendly Republicans in future primary elections. And indeed, in Alabama, they've poured money into the race to give Byrne an 8-1 fundraising advantage. The Chamber of Commerce alone has spent nearly $200,000 promoting Byrne's candidacy.

To be sure, extrapolating too much from one provincial race could be problematic. It is, after all, only one contest in one very, very Republican district, where GOP voters aren't necessarily representative of the party as a whole. (The district is so heavily Republican that former Rep. Jo Bonner (R), who stepped down earlier this year to set up the primary, captured 98 percent of the vote in 2012.)

Yet the race's overarching dynamic of establishment vs. Tea Party — and the extent to which the business community has gone all in to sway not a general election, but a primary — could serve as a microcosmic preview of what lies ahead for the GOP in 2014 and beyond.