Despite what you see in the apologetic leftist media, including Politico), Sasse was constantly under attack from the establishment arm (McConnell and Rove) of the Republican Party.   This is a big win for conservative principles and a big loss for Mitch McConnell.

(Via Politico)  Sasse, the former Bush administration official, received about 49 percent of the vote, according to an Associated Press vote tally with roughly two-thirds of precincts reporting. Omaha banker Sid Dinsdale, who had picked up last-minute momentum, received 23 percent of the vote and former state treasurer Shane Osborn received 21 percent.

[…]  Sasse also had endorsements from Sen. Ted Cruz and former Gov. Sarah Palin, both of whom attended a rally with him last month.

Dinsdale had hoped to capitalize on the mudslinging between Sasse’s allies and Osborn to force a repeat of the 2012 primary in Nebraska, when now-Sen. Deb Fischer pulled off an upset after the two well-funded front-runners destroyed each other on the airwaves.

The attacks on Osborn included a “swiftboat”-like ad in which three veterans question the integrity of the former Navy pilot. The ad stirred so much controversy that two TV stations stopped airing it.

Unlike Sasse, who had outside groups running negative ads for him, Osborn was forced to do the job on his own. His campaign targeted Sasse in an ad for being soft on Obamacare, citing a newspaper that says it was taken out of context.  (read more)