"Moreover, Trump bears some comparisons to Jimmy Carter. His personal popularity is poor, and he has proven largely unable to transform his party in policy terms. Moreover, like Carter he leads what is arguably a demographically declining coalition of older voters in shrinking states. And if you think Trump is a failed "disjunctive president" at a moment when the winds of populism are blowing, then Sanders is the obvious successor. He would be able to steal Trump's populist thunder, waving the White House's Medicare-cutting budget like a bloody shirt, much as Reagan was able to accelerate Carter's deregulatory reformism and military buildup. But Trump-Carter comparisons are limited by two facts. First, Carter not only was unable to transform his party ideologically (as Trump largely has); he was also unable to establish control of it institutionally. That is emphatically not the case with Trump, who continues to purge his administration of disloyal elements and has struck fear in the heart of nearly every Republican senator not named Mitt Romney. Trump has faced primary challengers in 2020, but nothing remotely on the scale of Ted Kennedy's challenge to Carter. The Republican Party in 2020 will be absolutely unified behind Trump."