There’s the rub - policy ideas are just that - ideas - getting them enacted is another thing. However, a strong leader can get them through - of course, obama got his through but only because of shenanigans and a Democratic Congress that passed everything he wanted - and a weak Republican opposition that also passed everything he wanted. Remember, policy ideas are just a blueprint and subject to being tweaked.
But effectively getting wrong ideas enacted (cf. Obamacare) is worse than getting no ideas enacted. Trump has opined favorably about single-payer, and despite avowed support of traditional marriage has also said his views on the matter are “evolving”.
Reagan was a great president because he combined strong leadership qualities with an unerring sense of sound policy. . . Trump, not so much.