Like many big law firms, Jones Day, whose roots go back to Cleveland in the late 1800s, has prided itself on representing controversial clients.
Now Jones Day is the most prominent firm representing President Trump and the Republican Party as they prepare to wage a legal war challenging the results of the election. The work is intensifying concerns inside the firm about the propriety and wisdom of working for Mr. Trump, according to lawyers at the firm.
Doing business with Mr. Trump — with his history of inflammatory rhetoric, meritless lawsuits and refusal to pay what he owes — has long induced heartburn among lawyers, contractors, suppliers and lenders. But the concerns are taking on new urgency as the president seeks to raise doubts about the election results.
Some senior lawyers at Jones Day, one of the country’s largest law firms, are worried that it is advancing arguments that lack evidence and may be helping Mr. Trump and his allies undermine the integrity of American elections, according to interviews with nine partners and associates, who spoke on the condition of anonymity to protect their jobs.
At another large firm, Porter Wright Morris & Arthur, based in Columbus, Ohio, lawyers have held internal meetings to voice similar concerns about their firm’s election-related work for Mr. Trump and the Republican Party, according to people at the firm. At least one lawyer quit in protest.
Already, the two firms have filed at least four lawsuits challenging aspects of the election in Pennsylvania. The cases are pending.
The latest salvo came on Monday evening, when the Trump campaign filed a suit in federal court in Pennsylvania against the Pennsylvania secretary of state and a number of county election boards. The suit — filed by lawyers at Porter Wright — alleged that there were “irregularities” in voting across the state.
In recent days, Mr. Trump and his allies have been trying to raise money to bankroll their legal efforts. Some of the fund-raising entreaties have noted that a portion of donated money might be used to pay down the campaign’s existing debts, rather than to fund new legal efforts.
While it is not clear which law firms will be filing the suits, Jones Day has been one of Mr. Trump’s most steadfast legal advisers.
As Mr. Trump campaigned for president in 2016, a Jones Day partner, Donald F. McGahn II, served as his outside lawyer, leading recount fights in critical states. Mr. McGahn later became Mr. Trump’s White House counsel, before returning to Jones Day.
At the time, some senior lawyers at Jones Day objected to working closely for a polarizing presidential candidate, according to three partners at the firm. They grimaced at the sight of Mr. McGahn standing with Mr. Trump onstage after he won the New Hampshire primary in February 2016. A month later, the firm hosted a meeting at its Capitol Hill office with Mr. Trump and Republican lawmakers as he sought to win over the party establishment.
The firm’s work for Mr. Trump has also garnered it…