It was one of those pleasant September afternoons when you can feel the heat of summer giving way as the seasons change. At Turner Field in Atlanta, 500 people from more than 90 countries showed up for a solemn yet joyful ceremony: They took an oath to became citizens of the country that is now their home.

Eddie Perez, the Atlanta Braves bullpen coach who became a naturalized citizen last year, led them in the Pledge of Allegiance. President Obama said in a video presentation: “You can help write the next great chapter of American history. No dream is impossible."

That evening, at a town hall in New Hampshire hosted by presidential candidate Donald Trump, there was a different feeling in the air. When Trump started taking questions, he was asked: “We have a problem in this country. It’s called Muslims. You know our current president is one. You know he’s not even an American. Anyway, we have training camps growing where they want to kill us. That’s my question: When can we get rid of them?”

“We’re going to be looking at a lot of different things,” Trump replied. “You know, a lot of people are saying that, and a lot of people are saying that bad things are happening. We’re going to be looking at that and many other things.”

Those widely varying reactions to people from other cultures are one of the major differences between the two parties competing for the presidency next year.

Trump currently is leading in Republican polls, and he got there by hurling fiery denunciations at undocumented immigrants, calling them “rapists” and “drug dealers.” For Trump and his supporters, the preferred path for immigrants goes straight back to their country of origin—he vows he’ll deport all 11 million of them. Most of his GOP opponents are also taking extreme stands against undocumented immigrants. One of the exceptions has been Jeb Bush, whose wife is a naturalized citizen from Mexico. It’s no coincidence that Bush has also been sinking like a rock in GOP polls.

Shortly after the 2012 election, Republican National Committee officials released a report outlining where the party needed to go to win future national elections. They contended the GOP should appeal to a wider range of voters, especially Latinos. “It does not matter what we say about education, jobs or the economy; if Hispanics think we do not want them here, they will close their ears to our advice,” the report said.

There has been a pushback against that report from Republican activists, who contend the party can ignore diversity and win elections if they just do a better job of energizing and turning out white voters. That’s the attitude embodied by Trump and most of the other GOP contenders.

Whoever ends up as the Democratic nominee—Hillary Clinton, Bernie Sanders, or Joe Biden—will take the opposing position on this issue, and propose a path to citizenship for those who entered the country illegally. Democrats want to maximize the voter turnout of blacks, Latinos, Asians and other minorities.  

Immigration is going to be a major topic of discussion next year, both nationally and in states like Georgia where there are large immigrant populations. The 2016 presidential election could be the ultimate field test of the differing theories on how far a party should go in reaching out to diverse voters.