Roots ? What roots ?
The Republican party has never really been ideologically united. Or even consistent. Never. Not even under Reagan.
This requirement is not traditional, it is new.
Yup.
There were more moderates in the Republican party back when Reagan was seeking the nomination. Reagan chose to stay in the Republican party and fight.
eh - i respectfully disagree - there was a time the party was united in small less intrusive, fiscally conservative government