The Republican Party has been divided before. There was Robert A. Taft versus Dwight Eisenhower, Barry Goldwater versus the moderate establishment, evangelicals versus pro-business Republicans, and more recently the Tea Party/Club for Growth/Freedom Caucus versus the GOP establishment.

But the current divide in the Party of Lincoln looks deeper and filled with more animus than ever.

Ultra-outsider Roy Moore looks to have an edge over establishment-backed Sen. Luther Strange in the September 26 Alabama GOP Senate runoff, and other insurgents are lining up to go after incumbents or establishment-backed Republicans in next year’s primaries.

The party establishment, led by Senate Majority Leader Mitch McConnell and House Speaker Paul Ryan, and supported by some deep-pocketed backers, has no choice but to devote considerable time and resources to these internal struggles.

Spending millions of dollars to fight off challengers from within the party isn’t an ideal way to spend your time, but it’s better than handing over the GOP to the most ideological and uncompromising in the party.

Preventing the nomination of another round of Todd Akins, Richard Mourdocks, Christine O’Donnells, Joe Millers and Ken Bucks is important to help retain Republican Senate seats and new opportunities, but it’s also a way of preventing the party from marginalizing itself completely.

Nominating Moore in Alabama would not cost the GOP a Senate seat in the general election, but nominating Kelli Ward in Arizona probably would.

More importantly, electing more confrontational conservatives, like Moore, Ward and Chris McDaniel of Mississippi, would help shape the national image of the GOP. Donald Trump has already done some of that, but nominating and electing more Tea Party/Freedom Caucus types would damage the party’s reputation even further in all but the most Republican and conservative states.

McDaniel, you may remember, ran against Sen. Thad Cochran in 2014, finishing just a hair under the 50% mark, which forced a runoff. Cochran won that runoff and went on to hold the seat in November, in part because plenty of Democrats supported the establishment Cochran in the runoff.

Now, McDaniel is mentioned again as a Senate candidate, this time as a possible primary challenger to GOP Sen. Roger Wicker.

I remember seeing McDaniel and two other conservatives – Ben Sasse and Idaho congressional hopeful Bryan Smith – introduce themselves to a meeting of conservative, free market campaign contributors and activists early in 2014. It was enlightening.

Sasse, who that cycle was elected to the Senate from Nebraska, talked about his background and experience, discussed his view of government and made a few funny comments to connect with the crowd and show that he was personable.

McDaniel (and Smith, who eventually lost his primary challenge to incumbent Republican Rep, Mike Simpson) talked mostly about the Founding Fathers and how the GOP establishment and Republicans-in-name-only were destroying the party and the country. He made little attempt to introduce himself except for his ideology. He wanted to show how committed and uncompromising he was.

A civil war now looks unavoidable for the Republican Party. And the likely fallout is obvious.

Where the establishment wins, insurgents will complain that the system was rigged or wealthy contributors bought the election. Embittered and only loosely tied to the GOP, many of those voters will walk away after the primary loss.

Where insurgents win, party insiders and pragmatists will be frightened. The winners will clean house, installing true believers in state party posts. In turn, the defeated will sit on their checkbooks in the fall, maybe even forget to vote.

Either way, the GOP loses.

“Not this time,” some will say, arguing that the partisan divide is so deep that the McConnell wing and the Tea Party/Freedom Caucus wings will eventually come together to elect Republicans and defeat Democrats.

Maybe, but I wouldn’t bet on it. Independents are likely to be turned off by Republican infighting, and a civil war, with each side lobbing accusations at the other, rarely ends happily. There will be enough open political wounds to give Democrats opportunities they otherwise would not have.

I’ve been around long enough to see more than a few political circular firing squads. I’m seeing another one form, this time within the GOP.