Why Trump Isn’t Vulnerable to a Primary Challenge

Harry Enten: “The five presidents — George H.W. Bush, Jimmy Carter, Gerald Ford, Lyndon Johnson and Harry Truman — who faced strong headwinds in the New Hampshire primary all had approval ratings among their own party members of less than 75%. The four presidents — Carter, Ford, Johnson and Truman — for whom the nomination was in doubt or dropped out of the race completely had approval ratings of less than 70%. The two presidents — Johnson and Truman — who dropped out completely had approval ratings of less than 55%.”

“Now, it’s not a perfectly linear relationship between approval ratings and primary difficulty for an incumbent president. The dividing line seems to be a 70% to 75% approval rating within your own party. Those above it do significantly better in primaries than those below it. It seems that when a president has an approval rating above the 70% to 75% line, prominent challengers are more likely to pass on the race.”

“Trump, of course, is well above the line right now. He actually has a higher approval rating among Republicans than Barack Obama did among Democrats just before the 2012 New Hampshire primary.”