The controversy over Indiana’s religious-freedom law highlights the most fundamental divisions that now define American politics. For all the recent talk that foreign policy or income inequality will dominate the 2016 campaign, the firestorm over Indiana is a reminder of the underlying power of values and social issues to shape political identity.

The debate over the Indiana law is the latest manifestation of long-standing tensions in a country undergoing rapid demographic and cultural changes. The clash between defenders of religious liberty and opponents of discrimination on the basis of sexual orientation highlights the chasm that now exists within the population.

Economic and national security issues certainly differentiate Republicans from Democrats, but the most passionate arguments now often grow out of the rapid shifts in cultural attitudes and the dramatic redrawing of the face of an increasingly diverse America.

On one side are those who hail those changes as evidence of progress in breaking down barriers and producing a more tolerant and open society. On the other are those who are fearful about the full impact of those changes on their own freedoms and on the values of faith and family they regard as elemental in the making of America.

The divisions seem almost irreconcilable and manifest themselves across a series of debates, from same-sex marriage and abortion to the science of climate change to the restriction of gun rights to public displays of the Ten Commandments to the role of religion in public life. From both sides now come charges of the other’s intolerance.

It’s clear where all this is heading. No one can hold back the demographic trends that will, eventually, make many states majority minority. Public opinion on same-sex marriage has moved faster than anyone could have predicted five years ago, particularly among younger people. As Adlai Stevenson said long ago: “There is a new America every morning when we wake up. It is upon us whether we will it or not.”

The Indiana politicians who enacted the new Religious Freedom and Restoration Act are now caught up trying to argue a legal case about what the fine print of the measure does or does not allow. But in a much larger sense, they have lost the debate, which is why Gov. Mike Pence (R) called on lawmakers Tuesday morning to act quickly to clarify the law. But Pence said repeatedly that he personally opposes discrimination against any one and that the new law does not sanction discrimination.

Condemnation has been so swift and strong that it has damaged the state’s reputation and threatens the state’s economic future. Major companies in and out of the state want the law repealed. The Democratic governors of Connecticut and Washington have taken steps to prevent state-funded travel to Indiana.

The Indianapolis Star, which long was one of the most conservative editorial pages in the country, filled its front page Tuesday with an editorial headlined “FIX THIS NOW.” The editorial called on Pence and Republican lawmakers to enact another law “to prohibit discrimination in employment, housing, education and public accommodations on the basis of a person’s sexual orientation or gender identity.”

The editorial also directly addressed Pence, who had declined during an appearance on ABC’s “This Week” program on Sunday to answer whether, under the new law, it was legal to discriminate against gays and lesbians. “Governor,” the editorial stated, “Indiana is in a state of crisis. It is worse than you seem to understand.”

Greg Ballard, the Republican mayor of Indianapolis, has asked lawmakers either to repeal the law or do what the Indianapolis Star recommended. He told National Public Radio on Tuesday morning that lawmakers in his state are missing “the bigger trend” and must recognize and adapt to the changing tides of history.

All eyes are on Indiana after Gov. Mike Pence (R) signed a controversial religious-freedom bill into law. The Post’s Sarah Pulliam Bailey explains what's in the law and why there's so much opposition to it. (Pamela Kirkland/The Washington Post)

Pence and his fellow Republicans in the Indiana legislature may find a way out of this crisis, though just how they hope to do that won’t be clear until new language appears.

But the debate over what they did already has become a defining moment in what will be the backdrop of the 2016 campaign, and there has been little nuance in taking sides. Republican presidential candidates have rushed to defend Pence and the new law. Hillary Rodham Clinton attacked it as a license to discriminate.

Former Florida governor Jeb Bush said on the “Hugh Hewitt” radio program Monday that the law isn’t discriminatory and only protects people acting on conscience from being “castigated” by government. He said it is important in a diverse country to be both “tolerant of people’s lifestyles” while allowing “people of faith to exercise theirs.”

Sen. Ted Cruz of Texas praised Pence for “holding the line” on behalf of conservatives against the “ongoing attacks upon our personal liberties.”

Clinton speaks for a generally united Democratic coalition that is younger, more diverse and more secular than that of the GOP. It is a coalition emblematic of the newer America that is on the rise. The Republican candidates speak on behalf of a conservative base whose members are deeply worried about the impact of the changes underway.

But the GOP coalition is fractured on this, with divisions between its business wing and its social and religious conservative wing. This creates pressures for candidates to strike a balance, but at this point, the party’s presidential candidates are tipping more in the direction of the social conservatives rather than the business wing, a decision that could have significant consequences.

However the controversy over Indiana’s law plays out, the fight likely will be seen as just one of many flash points in the cultural conflicts of a changing country. Republican leaders in Indiana may want this fight to go away, but the sharply divergent feelings that produced it will remain.