The vast majority regions that Russia currently occupied/demanding were overwhelmingly pro-Ukrainian (opposing to Russian aggression) before the invasion.
Or are you referring the annexation referendum or some vote results made under occupation by foreign military force?
If you brutally invade a neighboring country and force its people to make an annexation referendum at gunpoint, surely the result will favor you, and you can invade other countries wherever you want like that.
I had bookmarked more different polls, but I lost all after I renewed my PC :/ You can look into it and find more.