He was an ally of Governor Charles Evans Hughes and President Theodore Roosevelt.

He ran for governor himself in 1914 with Roosevelt's support but lost the Republican primary to Charles S. Whitman.

In 1901-1902, the three joined together to form Hinman, Howard & Kattell, an upstate New York law firm that continues under the same name today.

During his service as a New York State Senator, he became a key strategist and confidant of Governor Charles Evans Hughes.

Returning to the practice of law full-time, but continuing his call to public service, Senator Hinman was also influential in the establishment in 1949 of Harpur College, which would eventually become Binghamton University, and B.U.’s Hinman College pays respect to his leadership in this regard.