You don't have to rely on the polls or studies, just think back to the last 4-5 years, if you're able. I'll give you an example, to refresh your memory.
Remember the Trump Tower meeting? Kushner, Jr. and Manafort meeting the Russian spies? Jr. lied and lied about it initially. Jr. said the meeting was just to discuss adoptions while the news said the meeting was political in nature. MAGA Hatters called the allegations that it was political fake news. But eventually Jr. released the tweets showing the meeting was in fact to receive damaging information on Hillary Clinton. Did this change the minds of Trumpanzees? Of course not. They still insisted it was fake news.