The Baltimore Sun's Washington correspondent John Fritze takes a look at some of the candidates that might decide to run to replace retiring Senator Barbara Mikulski. (Kevin Richardson/Baltimore Sun video)

Baltimore Mayor Stephanie Rawlings-Blake could decide "within weeks" whether or not to run for the U.S. Senate seat held by the retiring Sen. Barbara A. Mikulski, according to a mayoral aide.

Rawlings-Blake has not ruled out running for the seat. Former Gov. Martin O'Malley, a Rawlings-Blake ally against whom she would be unlikely to run, said Tuesday he would not be seeking the seat. He is exploring a presidential bid.


Kevin Harris, a spokesman for the mayor, said O'Malley's decision has no influence on whether she decides to run for the Senate.

"The mayor's focus is on 2015 and what she needs to do for Baltimore City residents right now," Harris said. "There's plenty of time for 2016 politics. The only consideration in her mind, in terms of whether or not she would run in the race, is her obligation to the citizens of Baltimore, and serving them. It has nothing to do with who else runs in the race."

Baltimore will be holding a mayoral election in 2016, as well, and Rawlings-Blake is running for re-election, her staff said.

The Democratic primary race to replace Mikulski could be messy.

O'Malley is among the first high-profile Democrats to announce his intentions either way. Rep. Chris Van Hollen of Montgomery County is "highly likely" to consider a run, an aide said Monday. And Reps. C.A. Dutch Ruppersberger of Baltimore County, Elijah E. Cummings of Baltimore and John Delaney of Montgomery County said they are also interested in the seat.

On the Republican side, Rep. Andy Harris of Baltimore County and former Secret Service agent Dan Bongino are among a handful of politicians considering the race.