POTUS has clearly taking over the R party. He's certainly winning over many who were initially skeptical or downright hostile.
The real reason to vote R is to strengthen the hands of POTUS and to thwart the power lust of the Ds. In a few years the Rs will have changed to a political body that mirrors POTUS more than it already does.
There are a lot of anti political party folks here, and I fully understand those attitudes. But only POTUS can drive the change we all want to see.
What do you have to lose?