Sen. Bernie Sanders' win Tuesday in the Wisconsin Democratic Primary is not only his sixth straight win over challenger and frontrunner Hillary Clinton, but also proof that Sanders is still a contender in this race, according to political reporter Tim Murphy.

"The campaign is not fading. It's basically as strong as it's ever been," said Murphy, a senior reporter for Mother Jones.

Tuesday's victory earned Sanders a total of 48 delegates, while Clinton racked up 38 herself. That leaves Sanders with a net delegate gain of either 10 or four, depending on whether Wisconsin superdelegates who have already declared support for Clinton are included in the math.

All told, Clinton still leads by 210 pledged delegates following Tuesday's election. But while Murphy acknowledged that while Sanders still trails Clinton, he sees Tuesday's victory as a decisive one.

"It shows that Sanders is still very much a legitimate candidate and that Clinton has a lot of work to do if she wants to keep up," said Murphy.

David Martosko, the U.S. political editor for The Daily Mail online, agreed. However, he added that Sanders is running a campaign that "hopes against hope" that some of the superdelegates will defect from Hillary Clinton.

"Sanders is actually almost running neck and neck with Hillary Clinton in terms of the earned delegates, and if these superdelegates weren't an issue this would be a hotly contested race and we would be watching it as closely as we are the Republicans," said Martosko.