"Without allowing candidates to pay themselves, the only people who could afford to run for public office would be independently wealthy individuals who can afford to take a year off from making a living in order to run," Paul S. Ryan, vice president for policy and litigation at the watchdog group Common Cause said. 

Susan Lerner, the executive director of Common Cause New York, said the ethics commission had ceded its authority to Mr. Lhota in the email. She called on the transportation authority to hire an independent auditor to investigate Mr. Lhota’s web of conflicts.

“The situation has evolved so that Joe Lhota himself decides if Joe Lhota has a conflict of interest,” Ms. Lerner said.

“If this case is not the limit, then there may be no limit,” said Ben Thorpe, one of the lawyers representing Common Cause.

Anthony Gutierrez of Common Cause Texas called the ruling a severe blow to voting rights.

"It is time for Texans to take up the fight for fair maps by establishing an independent redistricting commission," he said. "In a democracy, politicians have no business choosing their voters, it is the voters who should be choosing their politicians."

“There remains no record of the operations and fundraising of your legal defense fund,” the letter said. “If a legal defense fund is not carefully set up and administered, there are many ways the Fund may run afoul of executive branch ethics rules. Given the large number of ethics scandals now under investigation at the EPA, further scandals should be avoided by you and the agency.”

“There are certainly grounds to open an investigation on the merits,” said Paul S. Ryan, vice president for policy and litigation at the campaign finance advocacy group Common Cause. “But the F.E.C. has been dismissing complaints that I think are much stronger slam dunks than this.”

Sara Henderson, executive director of Common Cause Georgia, a government watchdog group, said that such cozy relationships raised suspicions of pay-to-play.

“Lobbyists and elected officials should never be involved in business deals together,” she said. “It gives the impression that the lobbyist and their interests will find favor with that official when it comes to awarding contracts and determining public policy that might financially benefit them.”

Paul S. Ryan, head of litigation at Common Cause, a nonpartisan watchdog group in Washington, said the New York filing provides details of actions that could also violate a federal ban on campaigns funneling “soft money” through nonprofits.

“This involvement of the Trump campaign in the foundation’s disbursements right before the Iowa caucuses may very well violate the campaign finance law soft money ban,” Ryan said in an interview.

Much of the enforcement of New Mexico’s conflict of interest and vote recusal rules revolves around voluntary compliance and having other legislators police each other, said Viki Harrison with Common Cause New Mexico, which advocates for stricter ethics laws. New Mexico legislators are not paid a salary and serve only part-time.

“When you police yourselves there’s always going to be questions around transparency and cronyism,” she said.

Paul Ryan, a vice president at Common Cause, a government watchdog group, said Trump’s disclosure bolsters its Federal Election Commission complaint that the payment should have been reported by the campaign. Whenever Trump learned of the payment to Daniels -- which is still unclear -- he should have directed the campaign to report it, Ryan said.

“Donald Trump’s reimbursement of Michael Cohen puts him in the middle of a campaign finance violation that he once denied knowing anything about,” Ryan said. “It’s a...