The hypothesis is possible, but there’s no evidence to support it. In fact, historically there has been no relationship between how predictive the polls were at this point and how many people said they were paying attention to the campaign in the fall before primary voting.

It’s certainly true that voters say they are paying more attention to this campaign than to previous ones. Two weeks ago, 82 percent of Republicans and Republican-leaning independents said they were following the election “very closely” or “somewhat closely,” according to an ABC News/Washington Post survey.

These pollsters asked the same question in eight previous primary races with no incumbent president running for a given party’s nomination, and no more than 75 percent of voters in that party ever said they were following the campaign “very closely” or “somewhat closely.”
CYCLE PARTY FALL POLL LEADER PARTY VOTERS FOLLOWING CLOSELY WON NOMINATION 2016 Republican Donald Trump 82% — 2008 Democratic Hillary Clinton 75 2008 Republican Rudy Giuliani 74 2012 Republican Mitt Romney 74 ✔ 2004 Democratic Howard Dean 55 1988 Democratic Jesse Jackson 51 1988 Republican George H.W. Bush 51 ✔ 2000 Republican George W. Bush 50 ✔ 2000 Democratic Al Gore 44 ✔