The Democrats won the 1988 Texas Senate race with 59% of the vote. Trump will have won Texas with a bigger margin than Bush in 92 or Dole in 96.
Nevada has always been in play - it only failed to vote for the winning candidate in 2016 and 1976, in the last century.
Arizona has flipped because of an increasing Hispanic population, but also because of educated white migrants, largely from California.
www.telegraph.co.uk/news/2020/11/06/chillingeffect-gave-red-state-arizona-doseof-blues/
It's probably not a good idea to compare Miami-Dade now to 32 years ago - the Hispanic population was 35% in 1980, 49% in 2000, and around 69% today.
The equation for the Republicans is very different to the Conservatives - the US has a large minority population, and states such as Arizona will be majority-Hispanic in a decade or so.
Biden has won this election by spending lots of money campaigning towards white voters in Pennsylvana, Wisconsin & Michigan, which he has recaptured. Trump has won the largest Republican minority vote share since 1960, despite Black Lives Matter, despite being an evil racist, and so on www.washingtonpost.com/opinions/once-again-democrats-have-misunderstood-minorities/2020/11/05/6d55d668-1fa6-11eb-ba21-f2f001f0554b_story.html
The Tories don't need to care at all that they are no longer a force in Bradford, Yardley, Slough, Luton and other constituencies with large Muslim populations that they held or performed well in under Thatcher & Major.
Clearly most religions tend to be extremely conservative socially, whereas both the Democrats & Labour are socially very liberal. The black population of the US votes almost exclusively for the Democrats, but it is not a significantly growing force. Trump won Mississippi with 60% of the vote, while the population is 37% black, while Pennsylvania will give Biden the White House while it is 80%+ white.
'Minorities' are not a single group - the Tories have held Harrow East against trends in London by appealing to Indian voters (as distinct from other South Asians).
In the current US election then a few hundred thousand extra Hispanic voters in Arizona over the last however many years will certainly have helped the Democrats, but it's simultaneously possible for their to be more Hispanic voters but for those voters to be less Democrat-voting than in the past.
You need to appeal to the right voters in the right places to win elections - Corbyn did well in 2017 by appealing to middle-class liberals, but he was trounced in 2019 when working-class white voters abandoned generational support for Labour and switched en masse. It remains to be seen this is a permanent realignment - e.g., conservative parts of the South still have many Democrat remnants, such as Joe Manchin who won the Senate seat held by Democrat Ku Klux Klan leader Robert Byrd. Manchin himself is not a KKK member, but he does vote against abortion and so on and take pains to say that he is a conservative Democrat, because otherwise he would be toast before his extremely socially conservative constituents.
In the UK there are all kinds of Momentum types who hold seats where they have little in common with their constituents. That was true for many decades, e.g., the Peter Mandelson, a member of the Hampstead elite won thumping majorities in Hartlepool, as did Blair (Fettes & Oxford) himself in Sedgefield, symbolically captured by the Tories for the first time since WW2 in 2019.
I recently read this article in The Grauniad about a journalist who moved to Portland from London, and she was horrified that the US was not as liberal as she hoped www.theguardian.com/lifeandstyle/2020/oct/31/we-left-the-uk-for-portland-expecting-a-liberal-dream-that-wasnt-the-reality
It would seem that culture war issues should be more off-putting to voters in the US than in the UK since there are more of them - the UK religious vote is often Muslim and Labour-voting in spite of this, while the Christian vote is hardly an electoral force. Yet apparently Biden has just won an election by being slightly more appealing to educated white voters following 4 years of BLM, trans rights, and such like, while being less appealing to minority voters.
Clearly the likes of the Lib Dems & Momentum are batshit insane on trans issues, but I doubt that will stop them eventually doing all their craziness - if it doesn't put off enough voters in the US, it's not likely to do so in the UK.
Although perhaps without Trump the Democrats would have been hammered handily. And without covid, of course, he should have won at a canter.