rooster--the President did have a choice. To act as a serious President who tries to BROADEN his base. Persuade and convince more people to join that base.
But his "go to" strategy is to bully his enemies and pander to a shrinking base.
Make no mistake--Trump would be seeing a huge decline in the polls IF the Democrats did not look so radical and left wing with their proposals that are not anchored in possibilities. Warren is finally losing ground because her multi-trillion dollar proposal for Medicare for All offends most moderate Democrats.
The sooner Trump wakes up (I am not holding my breath) and begins to present a reasonable case for moderates to support him (and not rely on the miscues of the Dems), the better it will be for the country.