With maintaining their majorities in the Legislature assured, Democrats have turned their attention, political maneuvering and deal-making skills to the selection of leadership for the 2018 session.

Senate President Steve Sweeney guaranteed another term for himself when, after rumors of an impending challenge began to circulate, he released a statement from a nearly unanimous Democratic caucus pledging support.

Assembly Speaker Vincent Prieto, D-Hudson, hasn’t been so lucky.

He faces an insurgency allegedly masterminded by Sweeney and South Jersey political power George Norcross, who convinced little known Assemblyman Craig Coughlin, D-Middlesex, that with their support and political clout, he’d make an outstanding speaker.

Coughlin quickly announced he enjoyed the support of as many as 30 colleagues, more than enough to oust Prieto and elevate himself. The base of his support is the 13 members who represent South Jersey districts and are allied to one degree or another with Norcross.

Prieto, though, has made clear that if there is a coup in the works, it won’t be bloodless.

He announced his own intentions to seek another term, expressing confidence he enjoyed the support of a majority of his caucus, including the large delegation counties of Bergen, Passaic, Hudson and Essex.

He forced the resignation of the longtime director of the Democratic Assembly Campaign Committee and took control of the committee and its fundraising program.

Coughlin hasn’t backed down, continuing to insist he has secured more than enough commitments to replace Prieto.

Middlesex County Democrats have complained they’ve been largely overlooked, despite the county’s history as a strong and reliable party enclave, and are overdue for recognition.

There hasn’t been this much muscle-flexing since the final round of the Mr. Universe competition.

The movement to depose Prieto has its origins in the frosty relationship between the speaker and Sweeney. The two have differed on several major issues, most prominently development of a new formula of state aid to local education.

They have clashed also on the state assumption of Atlantic City government, North Jersey casinos and an increase in the gasoline tax.

Prieto has chafed at what he feels is the disrespect shown him and the Assembly by Sweeney and Senate Democrats who, he has complained, reach accommodations with Gov. Chris Christie, approve them and expect the Assembly to follow suit.

Prieto feels that Sweeney has ignored the Assembly as a co-equal legislative body, refusing to consult or seek input from it.

The slights — deliberate in Prieto’s view — diminish his leadership and relegate the Assembly to rubber stamp status.

The public involvement of Norcross in the anti-Prieto movement is significant as well, representing in the minds of observers a serious move to extend his and South Jersey’s influence north of Interstate 195.

Despite occasional forays into North Jersey, Norcross’ political clout has largely been regional.

He has enjoyed a close relationship with the governor, an association that has paid off handsomely in the form of tax breaks and economic incentives for the city of Camden in particular.

If Coughlin succeeds in his challenge to Prieto, it will greatly strengthen Norcross’ hand, giving him close allies in the presiding officers of both houses of the Legislature.

Should Democratic gubernatorial nominee Phil Murphy succeed in November, his legislative and policy agenda will rest in the hands of Sweeney and Coughlin and — by extension — Norcross.

As presiding officers, Sweeney and Coughlin (if elected) would control the flow of legislation to the floors of their respective chambers and it would be necessary for Murphy, as governor, to deal with Norcross on issues of major import to assure a favorable reaction.

Such an outcome would enhance Norcross’ position as a statewide powerbroker and expand his sphere of influence.

The move on Prieto is not without risk, however. Should he turn aside the challenge from Coughlin, he’ll emerge a far more formidable figure.

He would be able to consolidate his power and make it clear that neither he nor the chamber he leads will automatically fall in line with the wishes of Sweeney or the Senate.

Historically, the jockeying for leadership positions doesn’t begin in earnest until the outcome of the general election.

The unprecedented early and highly public challenge to the speaker is an indication of the stakes involved in what Democrats believe will be a unified government come January — control of both the executive and legislative branches.

The levers of governmental and policy power await. A decision on whose hands will grasp them will set the tone and agenda for the next four years.

Carl Golden is a senior contributing analyst with the William J. Hughes Center for Public Policy at Stockton University.