I think what we're more likely to see is the GOP leadership coopting the core ideas of the extremists while maintaining their own positions of power. It's what they seem to do.
Their underlying mission is still to increase the governmental influence of corporations and their super-wealthy donors. They manage it by motivating their electorate to vote against their own interests through misinformation or religious fervor or by grandstand moves that actually have no hope of success.
For example, the Republican representatives signing the amicus brief.
This thing with Trump is tricky though.