“After the March 8 South Carolina primary, Reagan had won New Hampshire with 50% and SC with 55%. Do I misread conventional history?”
He also won Vermont
HReagan won Vermont with 30% of the vote, pretty long way from a majority.
The real point is that the primary season usually leans toward one candidate fairly early. That candidate this cycle is Trump, and did he not have such high negatives, there wouldn’t be much doubt.