I don't remember Tatu being er "political".
I remember the obnoxious Dima Bilan, whose victory probably was the tipping point that finally drove Wogan away.
Hilariously, many Russians complained about Ukrainian Verka Serduchka's entry "Dancing Lasha Tumbai" which they claimed contained the words "Russia goodbye"
I do remember how Portugal coordinated its revolution by the timing of its eurovision entry on the night,, or rather how it then commemorated it with Madrugada (April dawn) the following year.
https://en.wikipedia.org/wiki/Madrugada_%28song%29