Christie. | AP Photo/Mel Evans

Its prospects are far from clear, but talk about the impeachment of Gov. Chris Christie is no longer relegated to whispers between insiders.

The prosecution’s opening argument in the Bridgegate case — which featured the claim that Christie was told of the George Washington Bridge lane closures as they happened by two high ranking Port Authority of New York and New Jersey appointees — brought the talk into the open.

Now Democratic lawmakers who control the Assembly and state Senate are watching the trial carefully to see if any more revelations could warrant the attempted removal of the governor from office.

“All we know are the coming attractions that were given to us by each of the attorneys during their opening statements. They’ve all told us there will be proof at the trial that he governor knew about this,” said Assemblyman John Wisniewski, who helped break the controversy open as the leader of a committee investigating the Fort Lee bridge access lane closures that tied up traffic for days.

“We don’t know exactly what that proof is,” Wisniewski said. “For instance, is it merely the photograph of the three of them talking before 9/11? That’s something we’ve already known about and in my opinion it’s hard to make a strong case for the photo alone that the governor knew.”

A Democratic assemblyman who refused to discuss impeachment publicly confirmed a Friday morning NBC New York report that legislative staffers have begun researching the impeachment process. No governor in the state has been impeached before.

The process would have to start in the Assembly. Earlier this week, the liberal group NJ Working Families called for Christie’s impeachment. Assembly Speaker Vincent Prieto, who would make the call to begin the proceedings, said through a spokesman he “won’t be commenting on the trial until it’s completed and all evidence has been presented.”

Still, even if the Assembly votes by a simple majority to initiate impeachment, it would then have to be tried in the Senate. Removing Christie from office would require a two-thirds majority there, which Democrats don’t have on their own.

That could be complicated by the fact that Senate President Stephen Sweeney, under the state constitution, would not be allowed to participate in the trial — a vestige of New Jersey’s pre-lieutenant governor system when the Senate president was next in line for the governorship.

Montclair State political science professor Brigid Harrison, who recently penned an op-ed that upped the intensity of impeachment talk, said that her interpretation of the constitution is that the Senate president would still be able to vote, though it might require some legal interpretation. The constitution states that the Senate trial would be presided over by the chief justice of the state Supreme Court and that “the President of the Senate shall not participate in the trial.” If Sweeney could not vote and the remaining 23 Senate Democrats were in lock step in favor of impeachment, at least four Republicans would have to join them to successfully remove Christie from office.

Barring damning new evidence, it’s hard to see Senate Republicans going that way. The governor has had tremendous sway over the votes of GOP lawmakers. Only once have enough Senate Republicans joined Democrats to vote to override Christie’s veto of a piece of legislation, despite dozens of attempts.

State Senate Republican Leader Tom Kean Jr. did not return a call seeking comment.

It’s also far from certain that Senate Democrats would vote in lock step to remove Christie from office. South Jersey Democratic power broker George Norcross, a close ally of Gov. Chris Christie, is the political benefactor for several of them, including Sweeney. Other Democratic senators have been staunch Christie allies, and one, Sandra Cunningham, is a personal friend. And Christie is close with Essex County Executive Joseph DiVincenzo, whose deputy chief of staff is Democratic state Sen. Teresa Ruiz.

Democrats would also be creating a political obstacle for themselves through impeachment. Christie’s popularity is mired at 26 percent, making him one of the least popular governors in the nation. He’s so disliked in New Jersey that Democrats are considered near shoo-ins to win the governorship in 2017.

Handing the governor’s office to Lt. Gov. Kim Guadagno, who is already laying the groundwork for a run in 2017, would not only give her the power of incumbency, but a potential easy way to make a fresh start while distancing herself from Christie.

“It’s easier to run against Christie’s legacy than it would be to run against Guadagno,” Harrison said.

Monmouth University pollster Patrick Murray said Wisniewski, who’s considering a run for governor, may benefit from impeachment. But it’s far from certain other hopefuls, like Sweeney, would welcome it.

“There’s too many gubernatorial wannabees that don’t want to deal with an impeachment and, two, an incumbent Kim Guadgano as their opponent,” Murray said. “The politics of it — there are too many people who have more to lose from that spectacle for a variety of reasons.”