In 2019, he ran for New York State Senate for District 57 against Austin Morgan to fill the vacancy left by the resignation of Catharine Young.

[6] Borrello was elected to the Chautauqua County Legislature in 2009, where he served four terms from January 1, 2010 to December 31, 2017.

In 2017, he was elected County Executive, succeeding Vince Horrigan, who decided not to seek another term.

[2] In June 2019, he defeated Allegany County Legislator Curt Crandall in the Republican Primary.

[8] He defeated Democratic nominee Austin Morgan in the general election.