This sentiment has been repeated by a number of journalists who cover Capitol Hill. When they're off the record, they'll bluntly describe Trump as a huge pain in the ass and a political disaster.
In public, however, they rarely raise any kind of objection and it's always in the most muted of terms.
The reason is simple, as Dent explains: "the base." This is the core faction of hard-right Republicans who still love Trump, the sorts who are habitual voters and wouldn't hesitate to vote for anyone further to the right who primaried a Republican who didn't stand with the President.
They are, in a phrase, plagued by moral cowardice. They put their own seat and party before the nation and just let Trump be Trump while privately grumbling and bitching.
The result is that the country is held hostage by the minority of people in "the base."
As recent election results have shown in Kentucky and Louisiana, however, the base's power has weakened. You can stand with Trump and win your primary next year, but the rest of us are angry enough to make sure you're defeated in the general election.
This won't matter to members of Congress in safe, gerrymandered districts where there aren't enough Democrats to make a difference in the general. But there are still several dozen swing seats where it will make all the difference in the world.