Reagan's appeal to nationalism in 1980 was key to his success, but little talked about since
As someone who has studied German history for many years, I've developed an interest in political nationalism. I've always found it a bit odd that it is a topic discussed so little in the American context by either historians or political analysts. Much of this oversight has to do with how Americans define their nationalism as "patriotism," a word with a more positive connotation.
Nationalism, of course, has been a powerful force in America from the beginning. The revolutionaries of 1776 fit the literal definition of nationalists perfectly. Nativism and the Know-Nothing agitators of the 19th century were an outgrowth of a particular strand of nationalism, and the the Civil War and Reconstruction were, from a Northern perspective, an attempt to reforge the nation, whereas the Confederacy tried and failed to construct a new one.
More recently, nationalism has been the great secret force in American politics, one that derives its power from the fact that no one ever says its name. I think Ronald Reagan is the best example of how nationalism can propel those politicians capable of using it. Back in 1976, when he almost successfully challenged incumbent Gerald Ford for the Republican nomination, he managed to boost his moribund campaign by going after the treaty to give the Panamanian government control over the Panama Canal. In 1980 his supply-side economic ideas were well out of the political mainstream, and yet he managed to win labor-heavy states like Michigan, where they would have been abhorrent. Certainly much of his success can be chalked up to economic crisis and lack of confidence in Carter's leadership, but those factors alone can't account for Reagan's success.
He was also campaigning in the midst of the Iranian hostage crisis, and five years after the fall of Saigon. A great many Americans felt that the United States was losing its place in the world, and Reagan, with his hawkish Cold War stance and promise to "make America great again" spoke to that nationalist resentment. If you doubt the power and force of that nationalism, just look at how crazy people in this country went when the United States defeated the USSR in hockey in the 1980 Olympics. In terms of the hostage crisis, he claimed that he would "get tough" and scare the Ayatollah into sending those Americans back home. (Never mind the arms deals that Reagan later made.) He was going to show the Soviets, who had just invaded Afghanistan, who was boss. I have not done the research to verify this, but my gut and reasoned intuition tell me that more "Reagan Democrats" went for the Gipper because of nationalism than the Laffer Curve.
Fast forward to today, where Donald Trump is confounding critics with his place atop the GOP polls. Not coincidentally, he has also used the slogan "make America great again," while in true Donald fashion claiming that it was all his idea. Pundits who talk about him being "the first post-policy candidate" have it all wrong. He is getting support through naked appeals to narrow, militant nationalism and is fully aware of this. His slogan, his nativist attacks on immigrants, his militaristic statements about the Middle East, and his laments that America is losing ground to China are all grounded in nationalist resentment, as is a great deal of his success. He doesn't need policies, "make America great again" is all he has to say and he will get support. He says it with great charisma, more than the likes that his sorry-ass opponents can do. (Ted Cruz has to be fuming that Trump is stealing his voters because Trump is saying much the same but he isn't a weak-chinned, insufferably priggish know-it-all. )
Trump may be a boorish, bigoted, ignorant jerk, but he is not stupid. It is obvious that he has seen how the Tea Party has driven the Republican Party, and that the Tea Party's battle cry of "take our country back!" is pure, unfiltered nationalism. That (white) nationalism is at the heart of birtherism and why Trump's birther past has not been a hindrance to him. Among the highly nationalistic Tea Party crowd, that stance is to be commended. Call Trump dumb all you want, but he seems much more aware of the presence and power of nationalism in American life than all of the mainstream pundits put together. That's also why the Trump campaign is a joke I'm not laughing at, because nationalism is a force with the potential to do so much harm, especially when those guarding against it don't take it seriously.