[M. Thatcher]

They've been wrong exactly three times since 1984 (chart at link):

Candidates who lead the most recent Iowa Poll one month prior to the Iowa caucuses often go on to win the caucuses

Source:

DeSantis says Iowa Caucus polling is 'never accurate.' We checked. Here's what we found

[TBP]

In 1984, 1992, 2004, and 2020, there were Republican incumbents, so you have to take those years out. That leaves 1988, 1996, 2000, 2008, 2012, and 2016. They've been wrong three of those six times, according to your liberal source. That's a pretty spotty record. The Register is wrong as often as it's right, being generous.