Union leaders joined Democrat Rick Nolan to announce their endorsement at a press conference in the Iron Range city of Virginia.
Union representative Bob Ryan said Nolan will fight for mining jobs and to rebuild the middle class.
"He is an effective leader who will put the working men and women of northern Minnesota first.," said Ryan. "He is someone we can trust to fight for jobs and work to preserve pensions, health care benefits and Medicare.
Ryan had harsh words for first-term incumbent Republican Rep. Chip Cravaack, saying Cravaack has done nothing for working families on the Iron Range.
"His opponent's radical Tea Party agenda balances budgets on the backs of the middle class, while preserving tax breaks for millionaires and billionaires, " said Ryan. "Chip Cravaack may be good at holding meetings and talking about mining jobs, but they are empty gestures. "
Nolan said he was proud to have the Steelworkers' endorsement and he pledged to work hard to protect existing mining jobs and bring new precious-metal mining jobs to the Iron Range.
"I will work tirelessly to remove bureaucratic impediments to permitting our taconite expansions as well as the PolyMet and Twin Metals projects, without harming the great outdoors we all enjoy," said Nolan.