One of the most recent examples came during a radio interview last month, when he said the M.T.A. has “an incestuous relationship” with “bad contractors” that profit off the agency.

“If I had my attorney general hat on, I might raise other possibilities,” Mr. Cuomo said, referring to the law-and-order job he held before becoming governor.

One thing Mr. Cuomo didn’t say: His campaigns have raised a lot of money from M.T.A. contractors.

How much has Mr. Cuomo raised from M.T.A. contractors?

Emma G. Fitzsimmons, J. David Goodman and Agustin Armendariz crunched the numbers for The Times.

Since Mr. Cuomo took office in 2011, his campaigns have received more than $3 million from M.T.A. contractors and industry groups that represent them. Donors with ties to the M.T.A., including board members, their employers and transit unions, have donated an additional $1.5 million.

Why does this matter?

What happens in the subways and on trains can affect millions of riders.

M.T.A. contracts are worth millions. Some states have passed laws that limit contributions from state contractors to prevent companies from trying to influence elected officials.