(CNN) Sen. Bernie Sanders went all in for his 2016 Iowa state director Pete d'Alessandro's congressional campaign.

He endorsed d'Alessandro in January, helped raise money for the bid, headlined a rally for him in February and narrated a television ad that first aired in May.

But it wasn't enough.

D'Alessandro finished third in the state's Third Congressional District primary on Tuesday, having been outraised by both the winner, small business owner Cindy Axne, and second place finisher, Eddie Mauro.

In an interview Tuesday, d'Alessandro credited Sanders for paving the way for his campaign, which he said wouldn't have been possible -- or lasted as long in what had been a deep and well-funded field -- without the "political revolution" they launched two years ago.

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