WASHINGTON, D.C. — The jobs of 160 workers at the Cleveland-Cliffs steel finishing facility in Zanesville, Ohio, were at risk earlier this year.

The Department of Energy had proposed a rule requiring new electrical distribution transformers, a part of the electric grid, to use a different type of metal — amorphous steel — that is not produced at the plant. Amorphous steel makes more energy-efficient transformers, but is manufactured in the U.S. at just one plant, Metglas, located in South Carolina.

Sen. Sherrod Brown, D-Ohio, helped lead a successful effort to water down the rule, which ultimately required just 25 percent of new transformers to use amorphous steel, while the remaining 75% can continue to use the grain-oriented steel manufactured in the Zanesville plant.

“We’re not the only ones that benefit from the work that they’ve done for us; the communities that surround us, the state and the country as a whole benefit from this,” UAW Local 4104 president Eric Spiker said at a visit to the Zanesville plant on Oct. 22. “Sen. Brown has been a champion of labor and has had our backs.”

Brown is hoping union workers return the favor on Nov. 5.

Ohio has 641,000 union members, comprising 12.5% of the workforce, according to data from the Bureau of Labor Statistics.

Traditionally unions have endorsed Democrats. While 59% of union members still align with the Democratic Party, according to a Pew Research poll, a sizeable number have drifted to the Republican Party.

Demonstrating that shift, two politically influential unions—the Fire Fighters union and the Teamsters union—have declined to endorse either anyone in the presidential race.

The Teamsters still endorsed Brown, along with more than two dozen other labor unions, including the AFL-CIO, United Steelworkers and United Autoworkers.

When asked, Brown said he was not afraid of declining support among rank-and-file union members for Democrats.

“I look at politics not left or right, or liberal conservative. I look at politics as who's on your side. My job as representing Ohio workers and the state is to fight for workers regardless of party,” Brown said. “My job will always be that. And it's why I win elections.”

After milling around with workers at the Zanesville steel plant, Brown also touted his focus on local issues over partisan politics, referencing his cooperation with Zanesville Mayor Donald Mason, a Republican.

“Mayor Mason and I have been good buddies for a long time. He’s Republican and I’m a Democrat. We look past that and do what we need to do for this city and this region.” Brown said.

Brown is further courting Republicans by touting his bipartisan work in Congress, as well as public endorsements from prominent Republicans like former Ohio Gov. Bob Taft and former Ohio Attorney General Jim Petro.

In the high-stakes Senate race, polls show Brown and Republican challenger Bernie Moreno are essentially tied. These key voter blocs could well make the difference in giving Brown a fourth term in the Senate.