Iowa has exposed the schisms in both political parties. They are deeper, and probably more durable, among Republicans.
As the caucuses kick off the 2016 presidential race Monday, former Secretary of State Hillary Clinton has a small lead over Vermont Sen. Bernie Sanders -- 45 percent to 42 percent -- though both candidates are very popular among the state's Democratic caucus-goers, according to the Bloomberg Politics/Des Moines Register Iowa Poll published this weekend.
Among Republicans, billionaire Donald Trump is leading with 28 percent, Texas Sen. Ted Cruz has 23 percent and Florida Gov. Marco Rubio, 15 percent. But the divisions are more pronounced than for Democrats: Trump gets negative marks from supporters of the other leading contenders.
"On the Democratic side, you just have a lot of mutual respect, says J. Ann Selzer, whose Iowa-based Selzer & Co. conducted the poll.
"The Republican side is more of a bitter war," Selzer said.