What exactly is meant by ‘America First’?

The primary slogan of the Trump movement is the simple, now-iconic appeal to “Make America Great Again.” Indeed, “MAGA” is so ubiquitous that it is now a metonym for the movement itself. But if the Trump movement has a second catchphrase after “MAGA,” it would be “America First.” Donald Trump routinely vows that he is an “America First” politician. Myriad Republican congressional candidates now…