Gun control, abortion, fracking, climate change, immigration, school vouchers, health care — the list of issues that Americans are at one another’s throats about seems endless.

Who can use which bathroom is now a federal case. It is us-versus-them politics, and it is always the same us and always the same them.

Even those who enjoy a spirited argument suffer from polarization fatigue. But there is no relief coming. Americans are highly polarized and have grown more so.

We may blame politicians, big donors, activists or the ideological media for this — but they are just intermediaries. They are not the source of polarization.

We are.

Since 1972, surveys have collected data on how Americans self-identify as liberal, moderate or conservative. About half of the public had chosen a side as a liberal or a conservative by 1972, and half considered themselves moderates or were unaware of their ideology .

By 2015, the split was 56 percent to 44 percent, with liberals and conservatives combining to outnumber moderates. A national shift of this size is significant.

This shift seems even larger because ideologies now are more clearly reflected by the political parties. As late as the 1980s, there still were a fair number of liberal Republicans and conservative Democrats. The parties, in effect, masked and muted the general public’s polarization.

As the parties realigned over several decades, liberals gravitated to the Democrats and conservatives settled in with the GOP. According to election exit polls, the share of the Democratic vote coming from liberals increased from 26 percent in 1980 to 43 percent in 2012. The Republican vote drawn from conservatives increased from 39 percent to 60 percent over the same period.

None of this will change soon. Demographic shifts — the passing of generations and the growing proportion of non-whites among U.S. voters — may move the center point a bit left, but it won’t narrow the gap between ideological partisans.

Granted, Americans can be brought together by shared crises, as they were during the Great Depression and World War II, and briefly after 9/11, as well as by widely shared periods of prosperity, e.g., the Roaring ‘20s and the placid ‘50s.

Unfortunately, the fires of polarization will be stoked in the months ahead by a contentious presidential campaign and by an angry, fearful electorate.

Further, members of the conservative side are beyond boiling; they’ve had it. A majority of this year’s Republican primary voters reported feeling betrayed by their own party.

What would dial down our overheated politics? Giving Americans what they have always wanted: peace and prosperity. They have gone without these for too long. Turmoil is too common, and our post-recession economy has sputtered to grow at barely 2 percent a year.

Robust economic growth and domestic tranquility would not erase our ideological differences, but a less stressed-out nation might be better able to cope with them.

James E. Campbell is a political science professor at the University at Buffalo, SUNY, and the author of “Polarized: Making Sense of a Divided America.” He wrote this for the Los Angeles Times.