Sen. Susan Collins, R-Maine, speaks during a Senate Intelligence Committee hearing on Capitol Hill in Washington on May. 5, 2020. Credit: Andrew Harnik | AP

U.S. Sen. Susan Collins on Tuesday was ranked as the nation’s most bipartisan senator for the seventh straight year.

That comes as the Republican senator is running for a fifth term in a nationally targeted Senate race and as her approval rating has slumped under Republican President Donald Trump.

Collins received the highest bipartisan score for the first session of the 116th Congress in the Lugar Center and Georgetown University McCourt School of Public Policy’s Bipartisan Index. Maine’s junior senator, independent Angus King, ranked as 45th on the index. That’s down from 28th last year.

In the U.S. House, U.S. Rep. Chellie Pingree, a Democrat from the 1st District, ranked 107th, up from 138th the year before, while U.S. Rep. Jared Golden, a Democrat from the 2nd District, ranked 117th. Golden, who won his first term in the House in 2018, was not included in last year’s ranking.

[Susan Collins faces bipartisan anger in Trump-era re-election bid]

Ranking is based on how often lawmakers co-sponsor legislation from those in a different party and their bills attract co-sponsors from across the aisle. Dan Miller, policy director at the Lugar Center, called Collins the “gold standard” for bipartisanship in Washington.

Collins, who has served in the U.S. Senate since 1997, also ranks as the second-most bipartisan senator over a 26-year period, behind only Lincoln Chafee, a Republican who represented Rhode Island in Washington from 1999 to 2013. After leaving Washington, Chafee ran as an independent for governor in Rhode Island and later joined the Democratic Party.

Collins has long touted her willingness to work across the aisle, drawing at times scorn and praise from Republicans and Democrats alike. In recent years, Collins most prominently bucked her party when she cast one of the three deciding votes that sunk the Republican-led effort to repeal the Affordable Care Act in 2017.

But she joined her Republican colleagues that year to confirm Neil Gorsuch to the U.S. Supreme Court and to pass a tax bill. She drew sharp criticism from Democrats in 2018 over her vote to confirm Brett Kavanaugh to the nation’s top court.

[What Margaret Chase Smith’s ouster could mean for Susan Collins]

In a statement, Collins said that the “spirit of bipartisan cooperation” is needed more than ever as the nation reels from the unprecedented crisis presented by the coronavirus pandemic.

Collins is up for re-election this November in what has become a nationally targeted race as Democrats look to flip the U.S. Senate. A March poll showed Collins in a virtual dead heat with Maine House Speaker Sara Gideon, a Democrat who faces a primary challenge from lobbyist Betsy Sweet and lawyer Bre Kidman.

Collins’ position heading toward the 2020 election has slipped since a June 2019 poll gave her a double-digit advantage over Gideon and as her approval rating has slipped under Trump.

Watch: An interview with U.S. Sen. Susan Collins

[bdnvideo id=”2726359″]