I asked this question on another discussion board (outside Agnostic):

Do you think the U.K. is more progressive and liberal today than how the U.S. is?

I got these responses from various people:

1. Today? It always has been!
2. It always has been we stopped the pilgrim fathers from discrimination against other people and they didn't like it so they went where they could carry on discriminating against others.
3. The US is not perfect, and tend to be too conservative for my tastes, but yes, the British are in a better position than the U.S. is in, though that says more about how badly the U.S. is doing than how well the U.K. is doing. With the White House Squatter’s latest move, that being to send unidentifiable storm into the streets of America, we are now on a precipice. The question is whether the republicans will pull away from Trump or continue to support his madness and authoritarian ambitions.
4. Yes, I would say the UK is more progressive and liberal than the US. There is no death penalty in the UK. We have Universal Health Care. The UK is classed as a ‘full democracy’, the US is classed as a ‘flawed democracy’.
5. Much more liberal, much more. As far as progressive goes it depends on the definition
6. As you’ll find published in various places, the UK Conservative party, which is the politically farthest right of the mainstream parties, occupies a very similar position to the US Democratic party, the furthest left of the mainstream US parties.
7. There are many examples of things that are socially acceptable in the UK that are less so in the US, such as Atheism, Dressing unconventionally, Rights to abortion - it’s a non-issue in the UK, Drinking in public places, Living with someone you’re not married to. I heard that only 40% of children in the UK are born to married couples. My sister (late 50s) has two teenagers and has never married her partner of 30 years, nor my daughter, hers of 6 years. They have a toddler.
8. We have professional politicians in the UK, not bankrupted rogue landlords or old film stars or the latest wanna be, a rapper. Our politicians are from different ethnicities and religions and some are openly gay. Abortion is legal (as it is in pretty much all modern countries.) and there’s no significant pressure groups trying to change that. Our children are not forced/ encourage to swear allegiance to anything, especially not something as obscure as a flag. Religion is not a part of politics or public life.
9. The UK is secular. Where as the US says it is then puts ‘In God We Trust’ on its money, in the way a religiously oppressive country would force a single religion on all its people. There is no requirement to be of any religion or not-be-atheist to hold a position in public office in the UK. There isn't anyone trying to get creationism taught in schools in the UK and certainly not in science classes. There are uneducated people in the UK but anti-vaxxers, flat earthers, creationists and other nutters are extremely rare compared to the US. Anti-science and anti-intellectualism are not phrases you’d ever hear in the UK, unless discussing a totalitarian regime or the US.
10. Certainly, though, by US standards, the UK is pretty liberal (it was our conservative party that legalised gay marriage), and by UK standards, the US is pretty far right. When comparing the two, superficial similarities in things like language, mask very large cultural differences. Travelling around, I certainly didn’t feel any more at home in the US than I did in Argentina for example (I speak fluent Spanish so language wasn’t an issue). Again, I’m not knocking the US or praising the UK, Both of them are what they are. But what they are isn’t similar, particularly in terms of politics, despite what the French say with all that “Anglo-Saxon” crap.
11. Traditionally, the word “liberal" has referred primarily to people who reject monarchy and favor democracy. The UK still has monarchy and nobility in a very real sense, and in that way, the U.S is fundamentally more liberal than the British are.
12. England has an official state church, with their monarch at the head of that church. America has no state church. Another fundamental aspect of liberalism. But since rejection of monarchy and state churches is kind of a given in the US, when we talk about being “liberal", we tend to be referring to other things.