3rd parties have not worked because they failed to produce a strong and viable enough candidate(s) not necessarily because of their policies, etc.
Ridiculous. Teddy Roosevelt was a strong and viable a candidate as you’ll ever find. If it didn’t work for him, it isn’t going to work for some delusional nitwit.
A bigger problem for third party candidacies is the monopolistic control of ballot access created by Repulicans and Democrats. These two parties have passed laws demanding higher filing fees, and huge petitioning requirements that ensure third parties will expend time and resources just to get on the ballot. Time and resources that could be better spent campaigning.