> Yang has gone from 0 to 1

Yang hasn't gone anywhere, he's been bouncing around in the same range for months with no systematic progress.

> and is going to see exponential growth as Iowa gets closer.

If he did something radical like doubling his support in Iowa in the, what, 10 days remaining, and the sources of support he gained were optimally distributed for him to move up positions, that would still only get him to fifth from his current sixth in Iowa, and he'd only be a little over half the support of #4.