Roughly only 5% of Iowans bother to show up for Caucus. It has not been a good indicator of who will win nomination.
For example HUckabee won in 2008 and Santorum won in 2012, the 2 election cycles with no incumbents running.
True enough. But a candidate like Trump winning it will really propel him past the point of no return.
Like he said, he wants to run the table. That starts with Iowa.