Kick Over the Traces
(To). Not to follow the dicta of a party leader, but to act independently; as a horse refusing to run in harness kicks over the traces.
“If the new member shows any inclination to kick over the traces, he will not be their member long.” - Newspaper paragraph, Feb., 1893.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894