Shakespeare once wrote, “What’s done cannot be undone,” but a powerful Democratic Party leader this week told Newark Mayor Cory Booker he needs to seriously take a crack at challenging that maxim, according to two sources.

The New Jersey Democrat told Booker to call the White House and get President Barack Obama to call former Gov. Dick Codey and tell him to challenge Christie.

Codey has a scheduled trip to Washington, D.C. next week in search of money as he tries to hash out his gubernatorial plans.

In the meantime, “You’ve got to do this,” the source said the Democratic Party power player told the mayor, reflecting on the fact that Booker went to the Democratic National Convention in Charlotte with many in his own party believing he was their best option to go up against Republican Gov. Chris Christie.

At the time, the popular leader didn’t de-fuse the gubernatorial hoopla - then waited until just before Christmas 2012 to announce he wouldn’t challenge Christie but instead would run for the U.S. Senate.

This week the elder party Democrat dialed Booker up and told him, look at what you’ve done, you’ve put the party in turmoil by delaying your decision, now you’ve got to use your weight at the national level to rectify the situation.

“You need to impress upon him the need for a strong candidate,” the power player told Booker, according to the source.

So far, state Sen. Barbara Buono (D-18) is the only declared Democratic elected official in the race for governor.

The Codey for governor stories didn’t intensify until after Booker made his own announcement that he wouldn’t run, and the suspense is taking a toll on party members who want members to coalesce around a candidate.

At least one Democrat on today’s conference call for party county chairs blamed Booker for shortening the runway on the process.

“It’s a shame Cory Booker stayed in as long as he did,” the party chair griped.

Booker political strategist Mark Matzen did not return an email for comment.

A third source told PolitickerNJ.com that Booker and Codey - who have a strained political relationship these past four years - planned to meet this week regarding Codey's plans.