Political drama is brewing in the First Congressional District.

Richard Lazer, Mayor Kenney's right-hand man and deputy mayor of labor, is being wooed by union leaders to run for the seat that local Democratic party boss U.S. Rep. Bob Brady has held for two decades.

Lazer, who grew up in Brady's district and has had a longtime relationship with the congressman, said he was "seriously considering" it.

But the reason behind this potential move remains a mystery. Many in Philadelphia's political circles wonder whether Brady is scheming to install Lazer as his successor, while others speculate that the building-trades unions see Brady as vulnerable and want to make a power move.

Brady's top two political aides, Ken Smukler and Don "D.A." Jones, were indicted in October on federal charges for paying the campaign of a one-time primary rival $90,000 after he dropped out. Many people still wonder whether Brady will also take a fall.

Another theory is that Lazer is simply trying to raise his profile.

"It's a head-scratcher," Delaware County Democratic Chairman David Landau said.

"We have other races to run, we have Pat Meehan in the Seventh" Congressional District," Landau said, referring to one of the Republican seats Democrats are targeting this year. "We should be putting Democratic resources into other races, but to precipitate a primary against a guy like Bob Brady doesn't make sense."

Landau said Brady is popular among voters in Delaware County because of his constituent services and what he called a progressive voting record. The First District runs from the Northeast river wards to South Philadelphia and across into Chester, Swarthmore, and parts of Upper Darby.

"Any challenger would find it difficult to beat him," Landau said, adding that he will back Brady no matter who jumps into the race.

Assuming, of course, Brady does run.

Brady said in a brief interview Tuesday that he is seeking reelection and doesn't believe Lazer will run.

"I don't know what to tell you, people say what they want," Brady said. "I'm out campaigning… I'm running."

But some who have been around Philadelphia politics for a while don't buy it. They believe that Brady will pretend to run and pull out when the primary ballot is set, or even after the vote.

If Brady were to run, win the primary, and then drop out before the general election, Philadelphia ward leaders and Delaware County precinct leaders within the district would get to pick the Democratic nominee. As city party chairman, Brady has sway over the leaders of the 69 Democratic wards, and thus could have a role in hand-picking his successor.

One political operative said Lazer replacing Brady would be "a status quo bait and switch." Another said that if Lazer does run, it probably would be with Brady's blessing.

For his part, Lazer said that his decision does not hinge on what Brady does.

"I'm seriously considering it. I love public service. I love working here," Lazer said, pointing to City Hall as he stood outside the building. "I'm doing some soul searching."

Those close to Lazer say running for office has always been a dream, ever since he started interning with then-Councilman Jim Kenney in 2004.

Frank Keel, a spokesman for building trades leader John "Johnny Doc" Dougherty, said Lazer is getting a lot of encouragement to run from Dougherty and others in the union movement. Brady, a union carpenter, has long enjoyed backing from the building trades, and losing it would hurt.

Lazer grew up in a working-class neighborhood and family. His father was a sheet metal worker and his grandparents and uncles were union members.

He met Kenney when both were members of the Jokers Fancy Brigade Mummers club. After Lazer graduated from La Salle University in 2007, Kenney hired him as constituent services director. Later, he named Lazer as his deputy mayor of labor.

Yet Brady said Kenney has assured him, in phone calls and texts, of his support — and the mayor has publicly declared he was for Brady. On Thursday, Kenney said through a spokesman he would not comment on the race until candidates have filed petitions to run.

Others are challenging Brady. Nina Ahmad, a former deputy mayor who launched her congressional campaign in December, released a statement Wednesday saying she has raised $579,000 – more than $400,000 of it a personal loan  – and  has $564,000 on hand.

Michele Lawrence, former regional president of Wells Fargo, is expected to announce for the seat on Monday.