Why a primary challenge to Trump is likely to fail
Several Republican lawmakers have said it is too early to answer whether they'll back President Donald Trump in 2020.
Yet barring some seismic event, Trump will most likely be their only viable choice.
Trump right now is adored by the Republican base. His favorability ratings among Republican voters are up significantly from before the 2016 election. His job approval rating (which is slightly different though tied to his favorability rating) in the latest monthly Gallup numbers is 85% among Republicans. Those numbers are quite strong and not predictive of a primary challenge.