Lawmakers who have represented tough districts understand that dynamic.
"You never know how many voters you're going to need from the other side," said former Republican Rep. Henry Bonilla, who represented a competitive West Texas district from 1993 to 2007. "It's wise to work in the middle."
The Cook Political Report has rated 14 freshmen's districts as competitive so far, and those incumbents have cosponsored legislation with members of the other party about 21 percent of the time. Meanwhile, their 44 first-term colleagues from safer seats have supported cross-party bills only 11 percent of the time, according to the Quorum data.
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Graham leads the pack of freshmen in competitive districts: 52 percent of legislation she has cosponsored has gotten Republican support. Democratic Rep. Brad Ashford of Nebraska is next, at 42 percent, and Republican Rep. Lee Zeldin of New York is in third at 29 percent, according to Quorum Analytics.
Down the road from the Capitol, at the party committees, these partnerships can elicit mixed feelings, helping endangered incumbents on one hand but also boosting targeted members on the other side.
Sere, a former National Republican Congressional Committee spokesman, gave an example: If the Democratic Congressional Campaign Committee sent a message blasting a Republican as a tea-party hard-liner, and that Republican teamed up with a Democrat the next day, it would undermine the Democrats' message.
But there's also some leniency granted to first-term lawmakers from competitive districts, who sometimes haven't yet built up extensive records or widespread name recognition.
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"I think both Republicans and Democrats will let their vulnerable members do whatever they need to do to come back, within reason," said CR Wooters, a former Democratic leadership aide now at the lobbying firm Mehlman Castagnetti.
Yet bipartisan legislative efforts often dwindle as the term progresses. As the next election nears, party leaders try to shut down that activity, fearful that it could help the other side.
"Very rarely do you get bipartisan cosponsoring in September of an on-year," Wooters said.
Several of the lawmakers denied that politics was at play.
"I literally don't think about what party someone is on while working on a bill," Ashford, the Nebraska Democrat, told National Journal. "I don't have a plan to say that I'm going to support a Republican bill in order to get Republican support."
The bills that the vulnerable freshmen have supported together run the gamut, ranging from legislation that would grant Social Security benefits to same-sex couples to a resolution that would recognize the Armenian genocide. One of the measures would create a new, simplified tax form for seniors.