This is probably the nail in the coffin of opponents of gay marriage. The demographics just aren’t in their favor, even young Republicans favor gay marriage by a small majority. It seems unlikely that the newly minted 18 year old voters are going to oppose gay marriage anywhere near their 75 year old granparents who they replace.
As for the ACA, that issue is far from settled. All the Supreme Court did was agree that the law is what it is. It could easily be repealed and replaced tomorrow if the Republicans can swing a supermajority in the Senate. You’ll hear plenty about the ACA in the 2016 presidental election.