The president has told advisers he wants to travel extensively and hold rallies and that he is looking forward to spending much of 2018 campaigning. He has also told aides that the election would largely determine what he can get done — and that he expects he would be blamed for losses, such as last week’s humiliating defeat that handed an Alabama Senate seat to a Democrat for the first time in 25 years…

But getting deeply involved in the midterms could be a highly risky strategy for a president with historically low approval ratings, now hovering in the mid- to low-30s in many national polls, and might be particularly disruptive in primary contests pitting establishment candidates against pro-Trump insurgents. Last week’s upset in Alabama — where Democrat Doug Jones defeated Republican nominee Roy Moore — came after Trump endorsed two losing candidates in both the primary and special election.