The GOP civil war that will shatter the party to pieces is now really on

Now that Donald Trump is the presumptive nominee, the Republican civil war that will break the party into pieces, possibly for good, is fully underway.

The biggest battlefront right now is Trump versus Paul Ryan . The House Speaker on Thursday said he was not ready to back the party's new standard-bearer.

"I think what a lot of Republicans want to see is that we have a standard-bearer that bears our standards," Ryan told CNN. "I think conservatives want to know, 'Does he share our values and our principles on limited government, the proper role of the executive, adherence to the Constitution? There are lots of questions that conservatives, I think, are going to want answers to, myself included. I want to be a part of this unifying process. I want to help to unify this party."

On Friday, RNC Chairman Reince Priebus told Politico's Mike Allen that he would attempt to broker a peace. He said he told Trump, "Listen, let me just, my view is, just relax and be gracious and I'll talk to Paul and we'll try to work on this."

There are a couple of factors at play for Ryan here. On a personal level, the House Speaker is clearly repulsed by Trump's calls to ban Muslim immigration, round up and deport all 11 million undocumented immigrants in a single year, rip up free trade deals and expand government spending. Shockingly, Trump posing with a taco bowl and wishing all Hispanics a happy Cinco de Mayo (a Mexican holiday that isn't even a big deal in Mexico itself) did not warm Ryan's heart.

On a purely political level, Ryan has to worry about his House majority and the GOP's Senate majority getting swept away in a Democratic landslide driven by Trump's massive unpopularity.

Ryan has a long-term plan for the GOP that does not include worsening the party's already dismal ratings among nonwhite women and all minority voters. Demographics in the United States are moving against Republicans, especially at the presidential level, and Ryan rightly fears that this will only be made worse by Trump raging across the country for the next six months as the Republican nominee.

The problem for Republicans of course goes well beyond Ryan versus Trump. Hillary Clinton supporters at this very moment are furiously calling around to big GOP donors who are terrified of Trump and looking to bring their cash over to the Democratic Party.

Virtually the entire GOP establishment including the last two Republican presidents and the last two party nominees have all said they would skip this year's party convention. That could leave Trump's coronation celebrated only by the likes of Sarah Palin, Ted Nugent and Gary Busey (along with New Jersey Governor Chris Christie, who is deeply unpopular in his own state).

These people have big fan bases among angry, white Republicans, but they could put on a show that will further alienate the rest of the nation and tarnish the GOP brand in potentially irreparable ways.

Trump's candidacy is also forcing many Republicans into impossible contortions. Texas Governor Rick Perry for instance once called Trump a "cancer on conservatism." Now he is an enthusiastic Trump backer who would be willing to serve as vice president. Senate Majority Leader Mitch McConnell took the route favored by many other Republicans, issuing a tepid statement saying he would back the GOP nominee.

These Republicans are motivated by several things. Foremost among them, they loathe the idea of Hillary Clinton becoming the president and believe Trump could moderate himself and wind up being a decent candidate and perhaps even a successful president.

But they also fear defying the very loud will of Trump's fervent and unshakable supporters.

The problem with this approach is that around 16 million Republicans (and independents who voted in open primaries) have voted against Trump in the Republican primaries, while around 11 million have voted for him. There is no question that Trump by the end of the process will have won more votes than any other previous GOP nominee.

But there will still be more Republicans who wanted someone else. The problem is they could never settle on who that other person should be.

They didn't want the establishment (Jeb Bush, Marco Rubio), they didn't want a Libertarian (Rand Paul) and they didn't want an evangelical Christian (Ted Cruz, Ben Carson, Mike Huckabee et al). So a large and unusual coalition rallied to Trump's braggadocio and bold promises that were endlessly spread to the nation via constant and largely uncritical television coverage.

Ryan, of course, realizes that the Trump phenomena is not likely to be repeated and is almost certainly not a broad enough coalition to solve the party's dilemma at the presidential level. And he could very well seek the GOP nomination in 2020.

So it could be potentially very damaging for him to associate himself with the Trump brand. Ryan envisions a party with a positive economic message that focuses on growth (including through expanding free trade) and inclusion rather than anger and division. But going too strongly against Trump could alienate a large chunk of the Republican base and make it hard for Ryan to get the nomination in 2020 or beyond. The entire Republican Party is going through a wrenching identity crisis. But it's more excruciatingly painful for the ambitious young House speaker than perhaps anyone else.

— Ben White is Politico's chief economic correspondent and a CNBC contributor. He also authors the daily tip sheet Politico Morning Money [politico.com/morningmoney]. Follow him on Twitter @morningmoneyben.

More From CNBC

• Top News and Analysis
  

• Latest News Video
  

• Personal Finance