“I have heard pundits who swear that with negatives in the vicinity of 70% Trump may be the only one of the top three or four GOP candidates who CANNOT win a general election.”
Yes, but there are other pundits, not employed by National Review, who would disagree.
Not to mention actual polls of likely voters, who, incidentally, directly impact elections results.
No need to get defensive. You may not have noticed the polls being conducted on likely matches in the general election. They bear the pundits’ opinions out. Trump does not do as well in a general matchup.