What happens if the President hates abortion and gay marriage (serious question)? Does he have any power to repeal/overturn, other than having access to the bul

What happens if the President hates abortion and gay marriage (serious question)? Does he have any power to repeal/overturn, other than having access to the bully pulpit? It's not like he can get elected and say "OK gay marriage is over now", which he could do to the NSA (whether he will is certainly up for debate).