Just as any religion must be more worried about heresy than disbelief, Trump’s cult-like takeover of the GOP cares more about purging the heretics than it does baptizing true believers.
It is, perhaps, ironic that a famous economist―one whom conservatives (as recently as the Tea Party movement) once admired―can best explain why Hurd’s retirement is symbolic of a toxic system. Friedrich Hayek’s most famous book, The Road to Serfdom, includes a chapter about “Why The Worst Get on Top.” Hayek was specifically discussing why this inevitably happens in totalitarian regimes (for example, how did Stalin, of all people, manage to succeed Lenin?), but it is a hallmark of many dysfunctional organizations where the most “ruthless and unscrupulous” are promoted.
The corollary to the notion that the “worst get on top” is that the best bug out.
That is precisely what is happening with the exodus of Hurd, coupled with the defection of Justin Amash, the 2018 defeat of center-right female GOP candidates (like Barbara Comstock and Mia Love), and the spate of retirements that have been announced in recent weeks.