PROVIDENCE, R.I. — A dispute between Democrats in the Rhode Island General Assembly is provoking unusually public discord, with some lawmakers openly challenging what they describe as the outsize power of the legislature’s top two leaders to set the state’s agenda.

Pawtucket Sen. Donna Nesselbush stepped down as the Senate’s deputy majority leader Thursday after rising to the floor to protest what she called an “undemocratic process” that promotes “hegemony.”

She was speaking, in part, of last week’s rise to power of the new Senate president, Dominick Ruggerio, and his swift maneuvers to demote two committee chairmen and replace them with allies. Ruggerio, a North Providence Democrat, told reporters Tuesday that he didn’t want “dissension within my inner circle.”

He said Friday he was “a little taken aback” by Nesselbush’s comments and would have liked her to remain in the leadership team.

It was a jarring power struggle in a Senate with a reputation for harmony under former president Teresa Paiva Weed, a Newport Democrat who resigned from her seat Friday. But even those who have protested Ruggerio’s recent decisions said the centralization of power has been gradual and didn’t start with him.

“There’s been a greater concentration of power in the hands of fewer people,” said Sen. James Sheehan, a North Kingstown Democrat who led the Senate’s oversight committee until Ruggerio pulled him from its chairmanship this week. “That’s unhealthy for the process. It’s just not good for democracy.”

In her speech, Nesselbush argued for broader reforms that would give more power to each senator and committee, allowing them to vote on controversial bills and show constituents where they stand.

Bills that don’t have the leadership’s support in both the Senate and state House of Representatives, led by Democratic Speaker Nicholas Mattiello, are routinely put into a limbo status known as “held for further study,” frustrating proponents who spend hours debating the same issues year after year.

A reform push to end that practice was quashed in the House earlier this year. Both chambers have voted to confirm their current procedural rules, meaning they will likely remain unchanged until a new set of lawmakers takes office in 2019.

John Marion of good-government advocacy group Common Cause Rhode Island said the state “has historically had a strong legislature and also a highly centralized legislature,” though he noted that Ruggerio is only its fourth Senate president. The lieutenant governor presided over the chamber until 14 years ago.