Bemoaning the way the ground under middle-of-the-road politicians is “melting like late-winter snow in Maine,” U.S. Sen. Susan Collins on Wednesday pleaded with those who don’t see compromise as a dirty word to become “just as fanatical as those on the far left and the far right.”

Speaking at the No Labels Problem Solvers Conference in Northern Virginia in an address broadcast on her Facebook page, Collins said the “small band” of moderates in Congress is constantly taking “incoming fire from both sides.”

She said those who were once applauded for building bridges between competing factions now face a growing number who would prefer “to blow up the bridge” and sharpen the political divide.

In an era when politicians in Washington almost always line up along party lines and often engage in rancorous squabbling with their counterparts on the other side, Maine stands out for electing senators who frequently find themselves in the no-man’s-land in between.

Collins, a Republican who’s served for two decades, is the most bipartisan senator on Capitol Hill.

The distinction comes from a partisanship index compiled by The Lugar Center and Georgetown University’s McCourt School of Public Policy which have studied how often members of Congress have worked across party lines since 1993. She’s topped its list for three consecutive years.

Collins also snagged the first Jacob K. Javits Prize for Bipartisan Leadership from the Javits Foundation, a lifetime achievement award given to her for her work in advancing “common sense reforms by finding common ground with members of both parties on many critical issues.”

But Collins does not stand alone.

Two of the three least partisan senators in that time hailed from Maine. In addition to Collins, former U.S. Sen. Olympia Snowe also ranked in the top three. In the 11 congressional sessions studied, Collins three times topped the list and Snow twice came out on top.

Sticking with a moderate outlook, difficult as it may be, is a Maine tradition. But Collins pointed out that things are changing.

Collins said that polarization is the result of an increasing fragmentation of news sources, allowing people to seek out material they agree with; an explosion in social media that lets like-minded individuals to gather virtually; and a “residential sorting” that is seeing politically similar folks living in the same areas so they don’t come in contact with those who have differing views.

She said last week in Maine she saw firsthand how far things have fallen.

Collins said she met one day with Mainers for Accountable Leadership, a progressive grassroots group, and heard their concerns for 40 minutes on a wide range of issues. Yet the next day, they were outside protesting her supposed lack of availability during an hourlong call-in radio show on Maine Public, she said.

“The lack of civility is really disturbing,” Collins said.

Blasted from the left and the right, she said, “is what it’s like to be in the middle these days. And it’s very difficult.”

Those who believe in listening to people from each side of the aisle are criticized, she said, “and in some cases despised,” a change from the past.

But, Collins said, she doesn’t believe that Americans are as split as it sometimes appears.

”I still believe that most Americans are in the middle,” she said.

In Maine, voters have been kind for decades to moderates seeking Senate seats.

The two other Maine senators ranked by the Lugar study — independent Angus King, who is serving his first term, and Republican William Cohen, who stepped down in 1996 — were each less partisan than more than two-thirds of their colleagues.

Even though most of the 227 senators who served in that time wound up with a negative score for partisanship, all of Maine’s senators had positive results.

Former U.S. Sen. Richard Lugar, an Indiana Republican who helped create the index, said that coming up with a high score for bipartisanship “is a strong indication that a legislator is prioritizing problem solving and open to working with the other party when possible.”

Only three other states have never elected a senator with a negative lifetime score for partisanship: Nevada, North Dakota and Virginia. And Nevada caught a break because the index doesn’t count the voting records of the Democratic and Republican leaders, including Harry Reid, the longtime Democratic leader who retired last year.

The partisanship study of U.S. House members is less complete.

But in 2015, U.S. Rep. Chellie Pingree, a Democrat from Maine’s 1st District, scored 99th out of the 438 members scored by the study, just enough to give her a positive score.

Maine’s other member of Congress, Republican Bruce Poliquin in the 2nd District, wound up in 191st place with the only negative rating given to any Maine politician in the report.

Overall, Democrats and Republicans are about equal in their partisanship. Both parties have members at the top of the list as well as the bottom.

The only independent other than King who’s included is Vermont’s Bernie Sanders. He is among the most partisan senators, holding the last-place position by a wide margin in the most recent survey of Congress.