Politics is a team sport, so it has always required a certain flexibility on matters of principle. But two recent studies suggest that, for many Americans, only one principle really matters: following the leader.

And the Trump administration is proving it in spades.

An idealized account of how we reach our political loyalties might look something like this: First, we study the issues, weighing the facts and the applicable ethical standards—liberty, justice, equality, fairness, etc. Having thought long and hard, we then reach a set of conclusions about the correct public policy. Then we look around to see who shares our conclusions. Finally, we align ourselves with them.

In fact, a great deal of research on the psychology of political affiliation says we do pretty much the exact opposite: First, we decide what team we're on. Then we learn what our team's collective view on a given issue is. Then we look at the principles and the facts, cherry-picking those that support our team's view and rejecting the rest as somehow flawed.

In one well-known experiment, political scientist Brendan Nyhan presented political partisans with news stories that contained incorrect information—e.g., that the Bush administration had banned stem-cell research. Nyhan also included a correction pointing out the inaccuracy. Partisans were actually more likely to believe the inaccuracy after reading the correction—a phenomenon called the backlash effect.

People seem to be hard-wired to act this way. Using brain scans, Emory University researcher Drew Westen found that the reward centers of the brain light up when partisans reject information that contradicts their political preferences, in the same way the reward centers of a drug addict's brain light up when he uses drugs.

This would be troubling enough if people were consistent in their beliefs. But they aren't. Far from it.

For instance: Four years ago, during the Obama presidency, a Washington Post-ABC News poll found that just 22 percent of Republicans supported a missile strike to stop Syrian president Bashar al-Assad's use of chemical weapons against his own people. But a poll taken after Donald Trump ordered air strikes for the same reason found that 86 percent of Republicans supported it.

The same phenomenon has played out with regard to Russia. Republicans used to view Vladimir Putin with hostility, and ridiculed efforts at rapprochement such as Hillary Clinton's "reset" button. Since Trump took office Republicans view Russia more favorably than Democrats do.

Democrats exhibit similar changes of heart. Although their views are more consistent on Syria, Democrats' positions on a host of other issues have shifted markedly. The anti-war movement that had bedeviled George W. Bush largely disappeared when Obama took office, as did concerns about the dangers of the national-security state—even though Obama ratcheted up both the war in Afghanistan and warrantless electronic surveillance. As one research paper put it, "Democrats, who had been motivated to participate by anti-Republican sentiments, withdrew from antiwar protests when the Democratic Party achieved electoral success."

Even political identity itself is undergoing a shift. The Atlantic reports on recent findings by two political scientists examining the views of the conservative base. Grassroots activists now judge senators with very conservative voting records—such as Jeff Flake of Arizona and Ben Sasse of Nebraska—as moderate, while deeming others with moderate records more conservative.

The researchers posit that this is because Flake and Sasse have sharply criticized Trump—never mind that Trump himself deviates from traditional conservatism on a whole host of issues, from free trade to eminent domain.

If they're right, then many people now define conservatism not by a particular set of principles or a coherent political philosophy. Instead, they define it by the identity of the leader of the Republican Party. Since Trump is president, what he does is ipso facto conservative. Therefore, anyone who criticizes him—even from the right—becomes "liberal."

The phenomenon even extends to issues of morality. A recent poll by the Deseret News finds that Republicans and Democrats have largely switched places on adultery by public officials: "Today, 57 percent of Republicans say it wouldn't affect their vote if a presidential candidate had an extramarital affair in the past, compared to 47 percent of Democrats. In January 2016, the figures were nearly reversed, with 48 percent of Republicans and 64 percent of Democrats saying it wouldn't matter, the survey reported." That's quite a change in less than 18 months—and quite a change from the Bill Clinton era.

Not all partisans change their views so easily, of course. Many Republicans remain deeply opposed to Donald Trump, and many Democrats disapproved of Obama's warmongering and Clinton's tomcat behavior. But for far too many, holding the right view on a policy question is far less important than being on the right team—or being opposed to the wrong one.