This is how I see it, the year you identify as the best decade (and you were a democrat in that decade), reveals your new politics:
1980 Democrats are FAR RIGHT today (and clearly now republican).
1990 Democrats are Right today (and now republican).
2000 Democrats are moderate today (and maybe republican, independent or democrat)
2010 Democrats are Left today (and likely still democrat)
2020 Democrats are FAR LEFT.
Conservatives are similar, but you just shift them two sections right, so 1990 Republicans are FAR FAR RIGHT now.
In 50 years we'll have very old trans men and women on the FAR RIGHT complaining that back in their day only natural Human beings could get married after changing genders, and that it should be illegal to marry a human that started as a Frog then a pig then a human through genetic manipulation.
edited to make it more clear, the year + politics of that year => spits out your politics today.