Below, I’ve listed past Republican candidates who (i) had less than 5 percent of the party’s
endorsement points as of the date of the Iowa caucuses, meaning they had very little support from the party establishment, but (ii) won at least 20 percent of the vote in Iowa anyway. There are six of these candidates, ranging from rabble-rousers like Buchanan to religious-right candidates like Huckabee, to another self-funded billionaire in Forbes.
The problem is that they didn’t go very far from there, winning an average of just 14 percent of the popular vote across all the remaining primary and caucus states that year.
Even a candidate who did a little better than that, retaining 25 or 30 percent of the vote, would soon be bypassed as the rest of the field consolidated down to one or two other establishment-backed alternatives. This is especially likely to be a problem for Trump. Contrary to what you may have read elsewhere, he’s actually not all that popular among Republicans. His favorability ratings among Republicans have improved since before he declared himself a candidate2 but remain in the bottom half of the GOP field and well below the standard of candidates who have been nominated in the past.