As Trump’s re-election campaign ramps up, one component of the effort is preparing for possible primary challenges. The president is solid with Republican voters and would almost certainly defeat any intraparty opposition. But incumbent presidents who faced primaries are in greater peril in the general election, a fact not lost on the Trump campaign and the GOP more broadly.

To minimize potential political hurdles for Trump, some state parties could move to scrap their 2020 presidential primaries. Already a long shot, the unavailability of one or more high profile primary contests could further hamstring the odds of any Republican who dares to run against Trump in 2020. There is precedent for this strategy, even when less uncertainty has swirled around the incumbent president.

In 1992, the Iowa GOP didn’t issue a presidential ballot during its caucus, to save President George H.W. Bush from being embarrassed by Pat Buchanan, who proceeded to defeat the incumbent in the New Hampshire primary. In 2004, when President George W. Bush was running for re-election, the South Carolina GOP skipped its presidential primary.