Have you not been paying attention over the last two election cycles? Biden won in 2020 because a record-breaking number of people voted. Same in the 2022 midterms. The expected red wave was a pathetic trickle thanks to record numbers of people going to the polls. The Democrats enlarged their majority in the Senate and the Republicans ended up with a majority in the House that it took 15 votes to elect a Speaker.
People, especially young people, are motivated to turn out and vote against Republicans. We are seeing numbers that no one has ever seen before.
That’s how you measure support. Polls mean nothing. 2016 polls said that Hillary would win. 2022 polls predicted a red wave, that Republicans would take both the House and the Senate with huge majorities in each.