A rare bit of Indiana polling shows that Sen. Joe Donnelly may not be long for the U.S. Senate.

An Indy Politics poll has Donnelly losing to Republican challenger Mike Braun, 47 to 43 percent. Conducted by Mason Strategies, the poll is the product of 600 interviews with likely voters and was conducted from Oct. 15-21. It has a margin of error of 3.9 percent.

Despite the four-point lead, and because of that margin of error, Stephen Spiker of Mason Strategies says the race is neck and neck. “When applying the margin of error to each candidate’s vote share,” Spiker told Indy Politics, “the race is statistically tied. However, two weeks before the election, you’d rather be Mike Braun than Joe Donnelly with these numbers.”

Another recent poll, this one by the Mike Downs Center for Indiana Politics at Purdue University Fort Wayne, put Donnelly ahead of Braun by just one point, 41 to 40. That's almost equally bad news for Donnelly, though. Even if Braun really is a point behind, an incumbent polling at 41 percent is an incumbent who's probably headed for defeat.

Of course, even just two weeks from the election, things could change. Donald Trump is president, after all. But taken together, these polls place Donnelly on the endangered list. He was one of the last senators to claim the mantle of being a moderate Democrat. Now, his days might be numbered.

One thing to keep an eye on as the race narrows is the libertarian candidate Lucy Brenton. She will not win. She could keep Braun from winning, however. Libertarian candidates historically do well in the Hoosier State. In the Indy Politics poll, Brenton enjoys three percent of the vote, and in the earlier Purdue poll, eight points. If she keeps sapping Braun’s conservative base, she could end up saving Donnelly.