“Source. All you need to know.”
So they’re all wrong then. What source would you like?
There are polls upon polls. The most relevant, of course, are the state polls of likely voters. We’ve only had a few. One was OH primary, where Trump beat Cankles by 35,000 votes, even while coming in second. Another are the polls in FL, OH, and PA that have Trump beating Cankles.
Plenty of evidence. He who has ears, let him hear, he who has eyes, let him see.