As the 2020 election season enters its early stages with President Trump’s approval ratings taking a further beating from the protracted partial government shutdown, we’re starting to see more articles about the potential for a primary challenge to Trump.

I am generally supportive of the idea of primary challenges against incumbents, and cheered when many liberal Republicans were taken down in primaries during the Tea Party era. I also think even losing primary challenges can be useful in furthering a specific idea, or putting pressure on an incumbent. A good example of this is Orrin Hatch, who became much more reliably conservative in the run up to his 2012 re-election race, out of fear that he was at risk of losing the Republican nomination without bolstering his right flank.

Challenges to an incumbent president are less common, but by no means unprecedented. Ronald Reagan challenged Gerald Ford in 1976; Ted Kennedy challenged Jimmy Carter in 1980; and Pat Buchanan challenged George H.W. Bush in 1992.