Kansas Gov. Sam Brownback, left, and  Sen. Pat Roberts greet each other at Johnson County Republicans' election watch party on Aug. 5 in Overland Park, Kan. (AP Photo/Charlie Riedel)

It's looking more and more like independent candidate Greg Orman has a real shot at beating Sen. Pat Roberts (R-Kan.) this year, after Democratic nominee Chad Taylor dropped out of the race Wednesday.

And if Orman somehow pulls off the win, it would be an historic one for independents. That's because Orman would be joining the largest contingent of independents in the history of the Senate. Orman would be the third political independent in the Senate, along with Sens. Angus King (I-Maine) and Bernie Sanders (I-Vt.), both of whom caucus with Democrats. (Orman hasn't said with whom he'll caucus, but it's likely to be the majority party.)

According to the Senate historian, the upper chamber has never had more than the two independents it currently has. And even if you lump together independents and third-party senators, the last time there were more than two was 1940.

Back then, it was a Midwest Thang: independent George Norris of Nebraska, the Progressive Party's Robert La Follette of Wisconsin and the Farmer-Labor Party's Henrik Shipstead and Ernest Lundeen of Minnesota.

(The Farmer-Labor Party in Minnesota merged with the Democratic Party in 1944, and to this day Democrats in Minnesota run under both banners.)

And before the late 1930s, you have to go all the way back to the turn of the 20th century -- before the direct election of senators -- to get more than two members who weren't Republican or Democratic.

Even as there is plenty of disgust with both major political parties these days, there has been little in the way of a legitimate move toward independent or third-party candidates. Having a third independent senator, though, wouldn't be nothing.

In fact, it would be unprecedented.