– U.S. Sen. Tina Smith is joining other Minnesota elected officials in supporting a land exchange to enable a proposed copper-nickel mine on the Iron Range, a move that aligns her with many other of the state's top DFLers but has faced strong pushback from environmentalists.

Smith is sponsoring a Senate measure to codify the land swap, already underway by the U.S. Forest Service, to make way for PolyMet Mining's long-in-the-works project. It would also nullify four lawsuits seeking to block the move.

"Land exchanges like this happen all the time," Smith said in an interview Friday. "Sometimes they happen administratively and often they happen legislatively — there is really nothing unique about this."

The Senate could vote on Smith's amendment as early as Monday. The House has already approved a similar measure sponsored by U.S. Rep. Rick Nolan, a DFLer whose district includes the Iron Range.

That Smith would get on board with the legislation is not surprising — fellow top DFLers including Gov. Mark Dayton and Sen. Amy Klobuchar have also supported the project; Klobuchar is co-sponsoring Smith's amendment. Still, opposition to the project remains strong among environmentalist groups generally aligned with the DFL, and Smith's DFL primary opponent is against the land exchange.

"Make no mistake — this is nothing more than corporate welfare," said Richard Painter, a former Bush administration official and high-profile critic of Donald Trump.

Smith said the measure would not circumvent federal environmental laws or affect the state's own rigorous environmental review process for the mine. She said that calling it a corporate giveaway was a mischaracterization, instead describing it as essentially an exchange of equal value between PolyMet and the government.

Under separate administrative action, the U.S. Forest Service plans to close on the transfer of 6,650 acres in the Superior National Forest to PolyMet on June 28. The company owns the mineral rights underground, but the federal government owns the surface land. The federal government would receive approximately the same acreage owned by PolyMet nearby.

PolyMet official Brad Moore said that with its action, Congress would essentially be ratifying the Forest Service's decision. But he said it's still important because "typically on these large land exchanges and mining projects, you have continual lawsuits — they just keep coming and coming." The congressional vote "would end those lawsuits," he said.

Moore said that PolyMet had already gone through an extensive public process during an environmental impact study, with public meetings and comments.

The plaintiffs in lawsuits against PolyMet are unhappy with that prospect.

"The fact that we and other groups who are based in northern Minnesota don't have the right to go to court is just plain wrong and not consistent with Minnesota values," said Paula Maccabee, advocacy director and counsel for WaterLegacy, an organization that is suing to block the land exchange. "It's not consistent with American values. It's not consistent with what we believe is the right of due process of law."

She said the "fundamental questions" of whether the public is being ripped off on the land exchange and if endangered species will be protected deserve their day in court.

Mining issues in northern Minnesota have divided the DFL, with some questioning their leaders' support for such projects. At the same time, Republicans have blasted leading DFLers for not doing even more to accommodate mining projects like PolyMet's.

The debate over mining has become particularly thorny for DFLers in the Eighth Congressional District. Nolan is not running for re-election, and the race to replace him is expected to be one of the most competitive in the country given Trump's win in the Eighth District in 2016.

DFL activist Molly Parker Hoof criticized Smith for accepting several campaign contributions from PolyMet officials and a miners' political action committee, and she asked why Smith would circumvent the courts. "I expect this behavior from Republicans, but not Democrats," said Hoof, of Carver County.

Smith responded that most of her campaign fundraising is from small, individual contributors. "My decision about ... this land exchange is based on what I think makes the most sense for Minnesota," she said.