Angus King recently took umbrage in this newspaper at criticism of his gubernatorial record by Charlie Summers. Both men, and their respective super PACs, are fixated on what happened — or didn’t — in the 1990s. Old news, in other words.

The real news is that despite their so-called differences, my two opponents have one key, disturbing trait in common — they love getting out-of-state money from special interest groups and powerful individuals.

Angus King, who likes to tout his independence, will be anything but, thanks to the millions of dollars he is getting from players like New York City Mayor Michael Bloomberg. Money comes with strings attached. Always. It is no wonder Mr. King doesn’t support the Dodd-Frank financial reforms — its implementation might hurt his new Wall Street friends.

And Charlie Summers, the Republican candidate, is reaping the benefits of the National Rifle Association — and its fat checkbook. Its president, David Keene, came up to Maine this week just to endorse Mr. Summers and to say this about Angus King’s recent windfall from New York: “Michael Bloomberg is an investor,” Keene said. “They put up $500,000 because they expect a return.”

Guess what? They all expect a return — the NRA, Mr. Keene, the Bloombergs of the world, the super PACs, the out-of-state millionaires.

Out-of-state money is buying Maine’s U.S. Senate seat. It is going to the highest bidder.

Maine needs a U.S. Senator who comes with no strings attached, who is beholden to no one’s checkbook. I urge Maine voters to support the candidate who matches their values and who will best serve our state, unfettered by past financial obligations, for the U.S. Senate.

Cynthia Dill is a state senator from Cape Elizabeth and the Democratic nominee to represent Maine in the  U.S. Senate.