In 1987, Thiele won a bid to represent the 16th District within the Suffolk County Legislature, a position he would hold for the subsequent four years.

In 1995, Republican Governor George Pataki appointed Assemblyman John L. Behan as New York State Commissioner of Veterans' Affairs.

Thiele ran for the seat and defeated Democratic nominee Leo Davis 69%–28% in the March 1995 special election.

[5][6] He won re-election for the first time as a member of the Independence Party, defeating Republican nominee Richard A. Blumenthal 59%–41%.

Thiele received a Juris Doctor degree from Albany Law School in 1979 and was admitted to the bar in New York in 1980.