This post is part of Polyarchy , an independent blog produced by the political reform program at New America , a Washington think tank devoted to developing new ideas and new voices.

If Donald Trump becomes the Republican nominee for president (as appears increasingly inevitable), the Republican Party will face a historically unprecedented dilemma. Unlike any party before it in US political history, the 2016 GOP will be saddled with a candidate who is entirely anathema to almost all its leaders and whom its leaders appear willing to go to great lengths to oppose.

This could be a great thing for the future of American democracy. That's because it could clear the way for a party realignment in American politics that would put an end to our current polarized gridlock.

Terrifying as Trump may be as a candidate, his rise has exposed the limits of the current Republican coalition. There is probably no putting the pieces back together now — especially if Democrats can exploit the divisions.

So here's my prediction: Over the next decade or so, the Republicans will split between their growing nationalist-populist wing and their business establishment wing, a split that the nationalist-populist wing will eventually win. The Democrats will face a similar split between the increasingly pro-corporate but socially liberally Clinton wing and a more economically progressive Sanders wing, a split that the Clinton wing will eventually win.

Eventually, the Democrats will become the party of urban cosmopolitan business liberalism, and the Republicans will become the party of suburban and rural nationalist populism (similar to what my colleague Michael Lind has predicted).

But this will take a while. And during the transition period, both parties will diversify to the point where they can again work within the uniquely compromise-dependent America system of separated institutions sharing power. As the parties weaken as coherent entities, the political system will become more fluid and dynamic, with more shifting coalitions and more opportunity for dealmaking, and less clear partisanship. For a while, American politics actually could be great again.

How the parties realign

I've made my prediction. Now let me explain how I see it actually happening.

My first prediction is that Clinton's general election strategy will be to cast herself a responsible centrist steward of American democracy in contrast to an erratic and fascist Donald Trump, working hard to win over the remaining moderate Republicans.

True, most Republicans concerned about Trump will not be able to bring themselves to vote for the hated Hillary Clinton, much as they may despise Trump. But some will, particularly once the Clinton campaign wins a few Republican endorsements. Perhaps Clinton even convinces a moderate Republican with swing state popularity (Rob Portman? John Kasich?) to be her vice president. At the very least, she'll probably win an endorsement from David Brooks.

As establishment business money panics at the potential of a Trump presidency, Clinton should see an opportunity. She can convincingly go to Wall Street and make it clear what a disaster a Trump presidency could be for global markets. She can speak to business executives and wealthy investors and quietly promise to push forward trade deals and other moderate business priorities once she is elected, and work for the immigration reforms the business community cares about. She can also quietly but credibly threaten them that there will be hell to pay if they oppose her.

Clinton could then use a record fundraising haul to both plaster the nation with a nonstop barrage of attacks on Trump and organize a record-setting get-out-the-vote effort in African-American and Latino communities.

Of course, the Sanders wing of the Democratic Party will grumble at Clinton's "selling out" as she tacks back to the political center. But given the threat of a Trump presidency, most will probably suck it up and vote for Clinton.

My guess is Clinton will win the general election solidly. She may lose some working-class votes to Trump, but she will pick up enough moderate Republicans to more than compensate. I also believe Democrats will win a narrow majority in the Senate on Clinton's coattails, particularly benefiting from her strong get-out-the-vote efforts.

As Republican leaders attempt to make sense of 2016 from their 2017 vantage point, they will have to face up to the simple reality that not only did a significant share of their voters prefer Donald Trump, but also the so-called establishment candidates (Rubio, Bush, Kasich, and, ahem, Christie) did not even combine to win as many as half of the voters.

Two camps will likely emerge in the Republican Party. One camp will argue that 2016 was a fluke, a black swan. They will argue for new primary rules for 2020 to pick a better establishment nominee (though at this point it's worth asking yourself who that uniting figure would be).

The other camp, which will include the acolytes that Trump will inevitably acquire as his campaign moves forward, will see Trump as the tribune of a new movement, the future of the Republican Party. They will argue that if Republicans are to win, they need to channel Trump's strong stances on immigration and political correctness and start taking principled stands against the sellouts and incompetents who are sapping America of its potential greatness.

Clinton and the Democrats could exploit the divisions by stacking their agenda with trade deals, modest immigration reform, corporate tax reform, rebuilding of infrastructure, college affordability, and possibly pro-business energy sustainability — a new set of wedge issues designed to force the Republicans into heightening the internal tensions.

Trump Republicans will, of course, oppose the Clinton agenda. But establishment Republicans may have a harder time opposing, given both business community support for many of these policies and the fact that these Republicans have actually supported some of these policies. Establishment Republicans will understand that if they oppose these issues, business support for the party could dry up.

As splits emerge in the GOP, it will be harder and harder for Republicans to unify behind a single leader. How long, for example, can Speaker Paul Ryan hold these factions together? At some point, he will either need to move to the center and make a deal with Democrats to run the House or he will need to decentralize the House enough so that each faction feels like it has a chance to advance its policies, thus leaning into the diversity within the party. The second will be a better strategy for holding the House.

Of course, the more Clinton forces these pro-business wedge issues on Republicans, the more she risks alienating the Sanders wing of her party, which is not going away. On some trade and business regulation issues, Sanders Democrats will build alliances with the Trump wing of the Republican Party, going against the establishment. Democrats will also have internal arguments about the future of their party.

And so the parties will become more internally diverse for a period of time. Partisan polarization will decline. At some point, the coalitions will sort out again, with Republicans most likely becoming a rural-suburban party of nationalist populism and Democrats becoming an urban party of cosmopolitanism. Then we will move back toward polarization. Until the next crack-up comes.

Obviously these are just guesses, and there are plenty of other possible scenarios one could envision. It's possible the Republicans could hold together more than I think they will in opposing an agenda designed to split them. It's possible Clinton operates as a traditional Democrat, sticking with the liberal positions she assumed in the primaries, and McConnell holds the Senate and stonewalls Clinton. It's also possible Trump wins the general election, and winds up just being a generic Republican, maintaining the current party alignment. It's possible a major war or an economic depression totally scrambles politics.

No political coalition is permanently stable

While it's hard to predict the specifics, the big-picture point is that all political coalitions in American politics have limited life spans. Issues and problems change. Demographics change. And both parties are locked in a perpetual struggle for an ephemeral majority, with losers always trying to pick off some potentially gettable group from the other side.

The most concise and convincing (to me) explanation of the transience of American political alignments comes from political scientists Edward G. Carmines and James A. Stimson, who in their excellent book Issue Evolution: Race and the Transformation of American Politics offer the following:

Thus, by their very nature, all party alignments contain the seeds of their own destruction, the various groups that make up the party may be united on some issues, particularly on those that gave rise to the alignment in the first place. But lurking just below the surface a myriad of potential issues divides the party faithful and can lead to a dissolution of the existing equilibrium. In politics, as Riker notes, because of the inevitability of internal contradictions, disequilibrium may only be one issue away.

We've arguably had six party systems in the United States. By "party system," I mean relatively stable coalitions that fight predictable ideological battles. Political scientists have long argued over whether realignments are "critical" (in that they happen as the result of a single election) or whether realignments are "secular" (in that they happen slowly over the course of several elections). The general consensus now is that realignments are usually "secular," in that they take some time.

Arguably, the current party system emerged out of the period following the 1964 Civil Rights Act, when Lyndon Johnson allegedly acknowledged that the Democrats "have lost the South for a generation." For about four elections, the parties were thoroughly scrambled, producing a time of low polarization and high legislative productivity.

But by 1980, the Republicans solidified around the Reagan vision for the Republican Party — strong on defense, traditional values, and free market economics. Most significantly, this offered a new and permanent home for the conservative Southerners who were now at odds with the increasingly effete libertine Democratic Party.

And once this party system was in place, polarization took off.

But this coalition was always an uneasy one (as all coalitions are in American politics).

Unpopular and costly wars in Iraq and Afghanistan have undermined American hunger for strong defense, reducing hawkish neoconservatism to a fringe movement among the voters.

Immigration has become a much greater concern, as the share of foreign-born people in America is now reaching levels not seen since the 1920s. In 2015, 13.9 percent of the US population was foreign-born, a steady increase from the 4.8 percent in 1965 when the Immigration and Nationality Act was passed.

Free market economics have eaten away at the living standards of white working-class men especially. Here it's important to note that for all Reagan's talk about fiscal conservatism, he understood he could not abandon the New Deal. After all, Reagan Democrats were working-class folks who depended on the New Deal welfare state. And Reagan himself was once an FDR Democrat.

In the intervening years, however, Republicans — in their headlong race to win over wealthy donors with promises to slash government spending by cutting "entitlements" — have forgotten this wisdom.

Donald Trump is the inevitable backlash. Working-class whites don't want entitlement cuts or balanced budgets. They want a government that they feel like is on their side, not the side of wealthy financiers or Chinese industrialists.

All this has created the conditions for Trump's nationalist-populist ideology to resonate with Republican voters, opening up a new idea of what it means to be a Republican.

So let us now gradually enter the seventh party system of the United States. If all goes well, American politics might actually be great again.