Nate Silver: Should Democrats Panic on Keeping the U.S. Senate?

538 reports:

The Des Moines Register’s Iowa Poll always makes news and with good reason: The pollster that conducts it, Selzer & Company, is among the best in the country, according to FiveThirtyEight’s pollster ratings. On Saturday evening, the poll had an especially interesting result in Iowa’s Senate race. It put the Republican candidate Joni Ernst six points ahead of the Democrat, Representative Bruce Braley. Most other recent polls of the state had shown a roughly tied race.

Consider the implications. Republicans need to pick up six seats to win the Senate. Right now, they’re favored to win the Democratic-held seats in Alaska, Arkansas, Louisiana, Montana, South Dakota and West Virginia, according to the FiveThirtyEight forecast. That’s six seats right there. In Kansas, however, the independent candidate Greg Orman is a slight favorite to defeat the Republican incumbent Pat Roberts — and Orman could caucus with Democrats if he wins. If he does, Republicans would need to pick up one more seat somewhere.

The odds.