This is true almost regardless of the final tally. If the Democrats win because of his presence in the race, Republicans may feel they must move in his direction. He would remake the Right at the cost of letting the Left remake the country. If, on the other hand, the Republicans win with a healthy majority, Buchanan will be marginalized. It would be folly to try to predict how well Buchanan would do in a general election.
Conservatism is a house with many mansions.
Buchanan is at war with the first two planks of this platform, and he is no longer reliable even on the moral issues, yielding as he has to other priorities. Where conservatives attribute our burgeoning underclass to moral breakdown, he blames capitalism. And he is willing to risk a permanently pro-abortion Supreme Court on a lark. Like Buchanan, Phillips is an old Nixon hand who decided at some point that exploiting cultural resentments and seeing various elites get their comeuppance mattered more than expanding freedom. The difference is that letting Buchanan continue to describe himself as a conservative would be not just irritating but destructive.