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ST. CLOUD, Minn. — Republican U.S. Senate candidate Mike McFadden declared, then quickly walked back, his potential support for a gas tax increase on Wednesday before aides whisked him away from questions about funding federal transportation projects.

McFadden said that, “yeah,” he could support raising the gas tax in order to bolster the federal highway trust fund as part of a revenue-neutral tax code overhaul. But not five minutes later, he revised and extended: “I just want to reiterate that I will not support raising the gas tax.”

Update: McFadden called this evening and said he “made a mistake” when he said he could support a gas tax increase, calling it a “band-aid” that “isn’t a long-term solution.”

McFadden said it would be unfair to raise taxes on drivers and that anyway the gas tax funding stream is likely to continue dwindling as a source of revenue as vehicles become more fuel-efficient (a claim backed by transportation funding advocates). Rather, McFadden said lawmakers should find potential spending cuts in the federal budget and use the savings to boost highway funding, in conjunction with an overhaul of the federal tax code.

“The way to come up with additional funds for transportation would be through a combination of finding wasteful spending that we’d be able to cut, and then prioritizing the other things that the federal government is spending money on,” he said. “Transportation, we need to fund it. We have roads that are falling apart, bridges that are falling apart and I want to have transportation funding be part of this overhaul.”

Of course, reforming both the tax code and the funding mechanism for highway projects is a big ask for a Congress that has shown little appetite for doing either.

But, McFadden said, “I would hope that there’s the political will to find a solution. The idea that you would just continue to raise the gas tax, I don’t think is a long-term solution.”

McFadden was in St. Cloud with 6th District congressional candidate Tom Emmer, fresh off their primary election victories Tuesday night, to talk with the area Chamber of Commerce when the subject turned to funding streams for the federal Highway Trust Fund, an account supported by the federal gas tax meant to bolster transportation construction around the country. Congress recently extended funding for the program through next spring, but lawmakers have long grappled with how to keep the fund from going insolvent as gas tax revenues fall.

McFadden said Congress should consider “a dramatic overhaul of our tax code” to fix the fund.

“In terms of revision of that, I started by saying you’ve got to decide where your priorities have been, where are you going to spend it?” he told the group. “And transportation absolutely is something that is a priority.”

Asked by reporters later for clarification, McFadden said he wants to “look at all taxes. I want something that’s revenue-neutral, so in aggregate there’s no tax increase, but it’s revenue neutral. We can figure out a more effective tax system in this country.”

Does that mean he’d consider increasing the 18.4 cent-per-gallon gas tax as part of a tax reform package?

“Yeah, as long as it was revenue neutral so that in the aggregate there is not a tax increase to the American public,” he said. “That should be a non-partisan issue, we say it’s revenue-neutral, it’s a special interest issue, I get that, but that’s why I think you need bipartisan support to do it.”

The subject moved to education, and the scrum soon ended as he headed off to another event. But McFadden talked to staffers and returned to the reporters:

“I just want to reiterate that I will not support raising the gas tax,” he said.

What about as part of a revenue-neutral tax code overhaul?

“No, no I won’t.”

Aides moved McFadden out of the room en route to another campaign stop before he could answer how he’d keep the trust fund solvent absent a gas tax increase.

Devin Henry can be reached at dhenry@minnpost.com. Follow him on Twitter: @dhenry