As Iowans finally prepare to caucus Monday evening, the state’s Republican voters and the dozen candidates jockeying for their support agree on one big thing: Barack Obama’s presidency has been disastrous for America and the next president’s mission must be, in front-runner Donald Trump’s trademarked phrase, to “make America great again.” But the two leading candidates, Trump and Ted Cruz, are offering these disaffected voters two very different solutions for how they would achieve this.