Iowa polls: Trump leads Cruz by 11, Sanders leads Clinton by eight

The sampling is key for both leaders: Only including voters who previously caucused in their party’s most recent competitive caucus, Cruz is neck-and-neck with Trump, with 30% for Cruz to 28% for Trump. Rubio is steady at 16% in that sample.

Of Democrats who caucused in 2008, Clinton leads Sanders, 55% to 38%.