There is plenty about GOP hopeful Donald Trump to which potential primary voters respond. He’s successful. He’s plainspoken. At a time when politicians are historically unpopular, he’s not a politician. And he has a great slogan.

That slogan resonates with his supporters, according to Republican pollster Frank Luntz, who ran a recent focus group, the results of which were written about in Time. “I used to sleep on my front porch with the door wide open, and now everyone has deadbolts,” one man told Luntz. “I believe the best days of the country are behind us.” Luntz concluded that people see Trump as a “real-deal fixer-upper,” able to make repairs that others have bungled. “We know his goal is to make America great again,” one woman astutely observed. “It’s on his hat.”

It could be on your hat too—Trump has begun selling “Make America Great Again” merchandise—if you can find one, that is. They have a tendency to sell out.

As Russell Berman pointed out in The Atlantic earlier this month, many white Americans these days are pessimistic to the point of despair:

White Americans—and in particular those under 30 or nearing retirement age—have all but given up on the American Dream. More than four out of five younger whites, and more than four out of five respondents between the ages of 51 and 64 said The Dream is suffering.

No wonder Trump’s message is so powerful—it’s a sugar pill coated with nostalgia. He is not promising to make America great, he’s promising to make it great again. But to what era does he intend to take the nation back? And what would that look like, practically speaking?