There's a straightforward argument for gay marriage based on bans essentially being discrimination based on sex:
A woman may marry a man, but a man may not.
Chief justice Roberts made this point during arguments in obergefell v. hodges.
And you're incorrect about the timeline. Gay marriage was approved of by a majority of Americans somewhere around 2011-2012. The supreme court decision was 2015. See my other comment in this chain for polling data.
“Rights” are what other human beings agree to recognize. That’s just the nature of law as a construct. What the federal courts in America have done is set themselves up as a tribunal of elites for deciding moral issues that other countries decide democratically.
This unsurprisingly causes a lot of friction. Same sex marriage actually wasn’t one of those areas—US opinion and that in other developed countries wasn’t far off, and it was legalized after it hit majority support. And Obergefell has a much stronger basis in law than other Supreme Court social decisions. There is a long line of precedent recognizing that marriage is a “fundamental right” protected by the constitution.
But abortion and religion in schools are examples of where the court is significantly out of step with both the letter of the law and public opinion. Public opinion in America supports abortion in the first trimester and or after that. That’s the same moral balance as reflected in the laws of say Denmark, France, Spain, Germany, and Italy (where abortion is generally illegal after 10-14 weeks). But under Roe abortion cannot be banned until the end of the second trimester. So our elite tribunal has imposed an abortion regime in the US that’s inconsistent with what more liberal Europeans have.
Same thing for religion in schools. 2/3 of Americans oppose the ban on school prayer. By contrast, instruction in public schools is a legal right in much of Europe, including the UK and Germany.
Being out of step with the public can be justified if that’s what the letter of the law requires. What’s most perplexing about Roe in particular is that it’s out of step with public opinion (broader than what the public wants) and also has no basis in the constitutional text. What’s the source of the court’s authority in that context?
> What’s most perplexing about Roe in particular is that it’s out of step with public opinion (broader than what the public wants) and also has no basis in the constitutional text.
This is false, Roe doesn't have “no basis in the Constitutional text”. It is true that the derivation of the understanding of rights articulated in Roe from the text is indirect, but that does not make it absent; it is a judicial understanding built on prior judicial understandings each of which directly or via even more intermediary judicial understandings derive from the text.
> What’s the source of the court’s authority in that context?
“The judicial power shall extend to all cases, in law and equity, arising under this Constitution, the laws of the United States, and treaties made, or which shall be made, under their authority”
A difference between us and Europe is that our country was founded on maintaining a separation between the state (which runs the schools we're talking about) and religion, and Germany wasn't. The entire premise of the Constitution --- really of any constitution --- is to insulate those kinds of governing principles from public opinion.
> House’s final version: “Congress shall make no law establishing religion.”
> The Senate responded with: “Congress shall make no law establishing articles of faith or a mode of worship.”
> The Conference Committee came up with the final version, “Congress shall make no law respecting an establishment of religion.” The Committee’s addition of “respecting an” was not explained at the time but has been the subject of a great deal of recent commentary. In its own time, however, the clause generated none of the heated arguments that had accompanied church–state issues in the states.
