Faith in American exceptionalism continues to decline, but Gov. Bobby Jindal is still hitching his wagon to Uncle Sam’s star in his presidential quest.

The belief that we are No. 1 is limited to a shrinking minority of all Americans, but polls show disaffection is particularly rife among the young. According to Pew Research, only about 15 percent of the under 30s these days are gung-ho for Old Glory.

The numbers would drop even further if Jindal ever were let loose in the White House, of course. But that is clearly not going to happen; given his record, he should be running not for office but, as the old joke goes, for cover.

Although American primacy is doubted in all age groups and across the political spectrum, Republicans and geezers are the most likely to retain the patriotic instinct. It thus makes some sense for Jindal to keep banging the drum. If the concept will play anywhere, it will probably be among the mossbacks and evangelicals who turn out in disproportionate numbers for GOP primaries and caucuses.

Jindal is so committed he suggests that “if you want to come here,” you must believe in American exceptionalism, although it is by no means clear how he would ensure that unapproved attitudes are kept at bay. Perhaps a President Jindal could station thought police at our borders. There must be some enhanced interrogation manuals still lying around in Washington.

That may not be necessary, for immigrants generally have a favorable impression of America, else they wouldn’t be immigrants. Any problems with assimilation will likely be down to the jaded native population.

Jingoism may be out of fashion, but most Americans at least believe that this country is among the greatest, which, when you look at some of the competition, isn’t much to write home about. It certainly isn’t enough for Jindal, who continues to aver that American exceptionalism is conventional wisdom. This nation of rugged individualists was taught to think that way at school, according to him.

But he believes we must be on our guard against liberal perfidy, and invites us to imagine what would happen if the federal government took control of history lessons. That, of course, is not about to happen, for Common Core applies only to math and English and in any case merely sets standards, leaving curricula to the states.

But Jindal evidently sees votes in the volte face that has made him such a foe of Common Core that he is doing his level best to banish it from Louisiana. Now he raises the specter of history teachers replacing stirring tales of exceptionalism with lamentations about “victimhood.” The bogeyman in this fantasy is clearly President Barack Obama. It wouldn’t work if we had a Republican in the White House.

Any idea that history might involve a search for objective truth evidently does not occur to Jindal. Instead, sound, reassuring Republican history must be defended against the un-American Democratic version. It is, of course, true that perspectives differ and that school boards must be selective when setting the curriculum, but there can’t be much difference of opinion when it comes to facts, whether pleasant or otherwise. Kids can surely revere the Founding Fathers and also confront the reality, say, of slavery.

But then having Republican history and Democratic history is easy enough, given that science can be reduced to partisan politics too. It appears that, whatever the data may say, for instance, Republicans are much less likely to believe in man-made climate change. Jindal stops short of outright denial, evidently believing it more politick to fudge the issue.

This is in marked contrast to his forthrightness on American exceptionalism, which has thus emerged as the last refuge of the scoundrel who wrecked higher education and public health care in his own state. Whether this is the greatest country on Earth will depend on what criteria are applied, but, if we are to be judged by our politicians, God help us.

James Gill’s email address is jgill@theadvocate.com.