There were fraud claims on the fringe just after the 2016 election. The evidence was sparse. It didn't take long for even those pretty angry about the election to realize fraud probably didn't happen, and if it did it was at too small a scale to meaningfully affect the results.
Unfortunately in 2020 the fringe became the GOP mainstream, treating equally soft claims as fact.
No, it wasn't "on the fringe". Note that this poll was taken in 2020, a full four years later.
"Seventy-two percent (72%) of Democrats believe it’s likely the 2016 election outcome was changed by Russian interference, but that opinion is shared by only 30% of Republicans and 39% of voters not affiliated with either major party."
By fraud I mean actual voter fraud. As in, effort was made to cause invalid votes to be counted or valid votes to not be counted.
Russia absolutely did and continues to push propaganda into elections in the USA and elsewhere. That's not really in dispute at this point so I'm not surprised it polls that high.
Got a poll that shows similar numbers for fraud? I would be genuinely surprised to see that.
> it’s likely the 2016 election outcome was changed by Russian interference
That sounds like a perfectly reasonable claim with evidence that supports it, paralleled by other elections in other countries as well; quite obviously very different to what was discussed above.
Unfortunately in 2020 the fringe became the GOP mainstream, treating equally soft claims as fact.