I have two.
Firstly, the press will overreact to the result on the Democratic side. The indications are that Clinton will either be run close by Sanders or even be defeated by him. If that happens expect journalists and pundits to start talking as if that indicates she is in real danger of not winning the nomination.
In reality, anything less than a crushing victory for Sanders is a strong indicator that he won’t be triumphant. As the chart below – which I’ve stolen from FiveThirtyEight – shows that Iowa is prime Sanders territory. There are only two states that have more of the white liberals that constitute his base: his home state of Vermont and the next event in the primary calendar New Hampshire.
After Iowa and New Hampshire, he will then have to compete in the much less favourable territory. If he does well in Nevada or South Carolina then that would be significant. Sanders doing well in a state tailor made for him to do well in would not be.
On the Republican side, my prediction is that whatever the outcome in Iowa the race will remain turbulent.
If Rubio were to win or come close in a state where ‘anti-establishment’ candidates like Trump, Cruz and Carson have dominated the polls, that would set him up with a clear path to the nomination. But that possibility seems remote.
If either Trump or Cruz can win decisively then they may be able to put an effective halt to the other’s bid. But the ‘establishment’ candidates already expect to do badly in Iowa and won’t be in any hurry to begin rallying behind a candidate they think will take the party to electoral disaster. I would therefore expect at least one of them to go on fighting even if they appear to be losing badly.
I therefore predict that come Tuesday the Democrat contest will look more exciting than it really is, while both the perception and the actuality of the Republican race will be of a brutal fight with plenty of time still on the clock.