Polls that show Braley trailing narrowly to Republican Joni Ernst also demonstrate how much Iowans dislike Obama. Just two years ago, the president won 52 percent of the vote in Iowa and capped his reelection campaign with a rally in Des Moines. By October 2014, Obama’s approval rating had dropped to 42 percent in a CNN poll and 40 percent in a survey from Fox News. Incredibly, an NBC News/Marist poll found only 36 percent of likely voters in Iowa backed the president – barely more than the share who say they support Obama in the Republican strongholds of Arkansas and Kansas.

Certainly, Democrats argue and Republicans acknowledge that the electorate’s opinion of Obama won’t solely determine this week’s results. But recent elections have demonstrated that Senate candidates who share a party with an unpopular president have – at best — a marginal capacity to win the votes of those who are unhappy with the White House.

And so this week, if Democrats somehow defy predictions and retain control of the Senate, they’ll have done so by demonstrating an unusual, collective talent for withstanding political headwinds along the lines of some of their party’s most celebrated victors of the last decade.

That – and not wandering chickens or ill-timed insults – is their biggest challenge on Election Day.