Next week when voters in Miami go to the polls, there will be two different Republican Parties on the ballot.

At the top of the slate will be Donald Trump, who’s running on a platform of sympathizing with white grievance, instigating mass deportation, shrinking America’s role in the world, closing borders and reducing trade, ignoring climate change, and warming the cockles of anyone inclined to believe a conspiracy about the global elites.

A few lines down the ballot will be Carlos Curbelo, a 36-year-old Cuban American running for a second term in Congress. Curbelo envisions a Republican Party as diverse as the country and his district, which runs from Key West through Miami-Dade County and Everglades National Park. Curbelo argues for America to continue its role as the world’s most indispensable nation. He values a country that is welcoming to immigrants and oppressed people throughout the world. He supports free trade and has actively campaigned on the need to address the effects of climate change that South Florida residents are seeing up close. In a recent interview, Curbelo cited his grandmother’s wisdom, “Los extremos son malos” — the extremes are bad. In July, he sponsored the DREAM Act, which would allow those brought into America illegally as children to become citizens. In filing the bill, he said:

A far cry from “rapists and murderers.” In fact, if an alien unfamiliar with U.S. politics listened to back-to-back speeches by Trump and Curbelo, you’d be hard-pressed to convince it that these two men come from the same universe, forget the same political party.

So the question that will face us Republicans after the election is clear. Which path should we choose, Curbelo’s or Trump’s?

A two-party system will always face internal factions and disputes, and we Republicans have long had our own internal push and pull between conservative elites and a populist “new right.” Matthew Continetti recently wrote a historical tour de force charting the history of the populist uprising within the party that highlights the roots of this tension.

But as intense as some of these past intraparty fights have been, there has never been a divide as stark as the one there is today about the direction of the Republican Party. In 2012, I was part of the team that wrote the RNC Growth & Opportunity Project — you might be more familiar with the liberal media’s preferred title: the GOP Autopsy. The report’s recommendations were so obvious they bordered on uninteresting. Upgrade the party’s data and digital operations, invest more in diverse communities, and offer a message that appeals to those communities.

The primary suggestion for messaging was to fix the Republicans’ “don’t care” problem and recognize that America looks different than it did in 1950. Trump ran a campaign whose central character trait was insulting others with a motto — “Make America Great Again” — that essentially called for a return to 1950.

In the area of grassroots organizing, we recommended more full-time GOP offices in minority communities, and, to the RNC’s credit, they followed up on that and made strides in an area we Republicans once mocked — “community organizing.” But organizing doesn’t work if the guy at the top of the ticket is rhetorically spitting at those you are trying to recruit.

I have to imagine that a statistician or a management consultant would look at the #twopaths forward for the party and not really understand why there is debate. The object is simple: get a majority share of the market. Curbelo’s path appeals to the growing part of the pie (nonwhite voters, young voters), while Trump’s path is maximizing market share in the shrinking part (white, older voters). No abacus needed.

But as we have seen, Donald Trump looked at the growth route and rejected it, deciding to use the GOP Autopsy as Trump Tower toilet paper. And he has prevailed. So any assessment of the path forward following his inevitable defeat next week has to take into account the factors that led to that success.

But those who are in the shrinking part of the pie — older, culturally conservative white voters who are more likely to respond to a nativist message — have a stranglehold on key parts of the party infrastructure. First, the presidential primary process is made up largely of these voters. The people who vote in the GOP Iowa Caucuses, for example, are overwhelmingly the same demographic year after year. There is always talk of which candidate can bring in new voters, but caucusing is habitual; and the only person in either party who has brought new voters to caucus with success was a uniquely suited candidate — President Obama in 2008.

The later primaries are more likely to include fresh blood, and Trump had some success bringing in new voters to the primary process. But studies of those voters by Politico and the Pew Research Center showed they were largely Republicans and Republican-leaning independents with a history of voting in general elections. Plus, they largely came from Trump’s working class base. When you consider the challenge ahead, remember that Trump and Ted Cruz together earned about 70 percent of the primary vote. A recent poll of Florida showed that if their primary was held today, Trump would still win with 35 percent of the vote — despite the fact it is the home state of Marco Rubio and Jeb Bush, and that Trump’s general election performance has been horrible, marked most recently by the tape of him talking about committing sexual assault and a slew of women coming out to say he assaulted them.

The voters who make up the primary electorate are the most engaged in the process, so it should come as no surprise that they are also the core audience for conservative talk radio and Fox News, and the most likely to make small-dollar donations directly to candidates or right-wing organizations. Anti-Trump conservative commentators have seen a drop in viewership over the campaign and some, like talk radio host Mark Levin, took so much heat for being against Trump that they reversed their view and now attack conservatives who hold the same position they held a few months ago. Gotta get those ratings!

So all of the individual, short-term incentives for Republican politicians are meant to appeal to this audience, rather than risk alienating them by trying to attract a broader electorate and increase their chances at winning the general election.

And it’s possible the results next week could further tip the balance against the forces for growth within the party. Trump will perform worst in areas with voters who are younger, more diverse, and highly educated — places that are currently represented by Republicans who want to move the party forward like Curbelo and Mike Coffman, who represents my hometown in suburban Denver. While internal polls show Curbelo and Coffman performing far better than Trump in their districts, there is concern that the “Trump effect” will depress Republican turnout in these districts so much that it will cause candidates like these to lose, leaving a party that has even fewer voices for reform and a greater percentage of elected officials beholden to white working-class interests than we have today.

For Republicans to become a successful national governing party again, we must bridge this gap and find a way to demonstrate that the concerns of the white working-class voters who flocked to Trump are being heard, while presenting a party that is welcoming to the rest of the country. Because as the electorate begins to look more and more like Carlos Curbelo’s America, the Republican Party is going to need to offer more candidates in his vein.

Otherwise we are going to continue to go down a demographic hole that leaves a party that is strong in rural America, the Old South, and parts of the Rust Belt — but not competitive nationally. The options that face the GOP are diversify or die. And many in our party are being drawn to death’s soothing siren song.

Tim Miller is a partner at Definers Public Affairs. He has been a spokesman for Jeb Bush, the Republican National Committee, and a bunch of other Republicans. He tweets a lot at @timodc.