[3] In 2018, state Senator Bill Beagle was term-limited, leaving the 5th district an open seat for that year's election.
As a result, Huffman opted to forego another term in the Ohio House to run for the Senate seat.
[9] During the 134th General Assembly, Huffman was assigned to the following Ohio Senate committees:[10] In December 2019, The Washington Post detailed how an editorial in the Sidney Daily News against Medicare for all by Huffman[11] was drafted with the help of lobbyist Kathleen DeLand of the pharmaceutical, hospital, and healthcare insurance lobbying group, Partnership for America's Health Care Future.
[12] In a June 9, 2020, hearing on whether to declare racism a public health crisis in Ohio, Huffman asked if it were possible blacks were contracting coronavirus at higher rates because "the colored population do not wash their hands as well as other groups".
[13] Ohio Legislative Black Caucus President Stephanie Howse said, "The fact that a well-educated legislator – a Vice Chair of the Health Committee and a practicing medical doctor – would, in a public setting, nonchalantly use such antiquated terminology paired with a hurtful, racist stereotype all in one breath reflects how unconscious this problem of racism is for too many.