On the other hand, progressive Senate Democrats like Elizabeth Warren of Massachusetts warned against passing the bill, arguing it would apply to too many banks and damage efforts to protect consumers after the financial crisis. Ahead of November's midterms, Democrats want to cast themselves as better defenders of workers and consumers than Republicans.
Voting on the bill largely reflects the midterm political realities. The Democrats running in safer seats this year tended to oppose the bill, while the lawmakers in races that election handicappers consider close were more likely to back the plan.
Ten of the 17 Democrats who voted for the plan will run for re-election this year. Seven of them — Heitkamp, Joe Donnelly of Indiana, Claire McCaskill of Missouri, Jon Tester of Montana, Joe Manchin of West Virginia, Debbie Stabenow of Michigan and Bill Nelson of Florida — face tough races in states Trump carried.
"You can't blame [Senate Minority Leader Chuck] Schumer for not wanting to twist the arms of red-state Democrats against home-state banking interests," former Schumer aide and Hillary Clinton advisor Brian Fallon told The Associated Press. "But from the standpoint of the larger party messaging, it's a missed opportunity to not strike a bright-line contrast on behalf of consumers."
Sens. Sherrod Brown of Ohio and Bob Casey of Pennsylvania, who also face re-election in states Trump won this year, notably opposed the bank plan. Both lawmakers appear to have an easier path to a November win than Democrats in more heavily Republican states like North Dakota.
The bill exposed fault lines among Democrats ahead of the midterms. In recent tweets, Warren hit her Democratic colleagues who supported the plan, saying it "wouldn't be on the path to becoming law" without her party.
Heitkamp told the AP "I came here to represent North Dakota, and that's exactly what I'm doing." She argued the bill "will make a huge difference for rural America."
Not just the vulnerable Democrats up for re-election this year backed the proposal. Sen. Doug Jones, who won a special election in deep-red Alabama last year, supported the bill. He will face another election in 2020.
Both senators who represent safe blue Delaware, Chris Coons and Tom Carper, backed the plan. The banking industry has a strong presence in the state.
Other Democratic senators not up for re-election but who represent swing states or want to be seen as moderate also voted for the bank proposal. Those lawmakers are Maggie Hassan and Jeanne Shaheen of New Hampshire, Gary Peters of Michigan, Mark Warner of Virginia and Michael Bennet of Colorado.
Some of those lawmakers also participated in a bipartisan group seeking a solution to end a government shutdown earlier this year.
Heitkamp's justification for backing the bill suggests more Democrats in red areas may have to shrug off national Democrats in order to compete in red areas, as Conor Lamb did in a House special election in Pennsylvania this week.
"I think people in North Dakota don't care what Elizabeth Warren thinks," Heitkamp recently told The Atlantic.