TAMPA, Fla. — Mitt Romney’s tightly choreographed nomination here was disrupted on Tuesday when a contingent of Ron Paul delegates from several states protested what they said were new rules by the Republican leadership to squelch their movement’s rise within the party.

Mr. Paul’s supporters shouted several times during the late-afternoon proceedings, and part of Maine’s delegation walked out in protest over a decision to strip away half the candidate’s delegates from the state.

By the time most Americans tuned in to the convention proceedings on Tuesday night, there was little evidence of the protests. But they signaled deeper party divisions bubbling under the telegenic surface of Mr. Romney’s nomination here, harking back to the primary season when Tea Party activists threw their support to a succession of Mr. Romney’s insurgent challengers.