From NBC's John Yang
CHICAGO -- The ripple effects of Chicago Mayor Richard M. Daley's decision not to run for a seventh term continue to reverberate -- and are likely to be felt in this November's election.

The immediate effect is to limit to pool of potential campaign contributions for Illinois Gov. Pat Quinn (D) and Senate nominee Alexei Giannoulias (D), both locked in tough battles to keep those offices in Democratic hands.

To win the Chicago mayor's race -- which will almost certainly be decided in a runoff on April 5, 2011 -- a candidate not named Richard Daley will likely have to spend upwards of $7 million, political professionals estimate. That's money that won't be going to either Quinn or Giannoulias. The late Richard J. Daley amassed so much power in the Chicago mayor's office, which his son consolidated, that its occupant is much more important to many big Democratic contributors than whoever is governor or U.S. senator.

The mayoral race already seems to have sucked all the oxygen out of this fall's two top statewide races at the very time Quinn and Giannoulias need to energize and unify the Democratic base in Chicago -- the key to success for any statewide Democratic candidate.

The aftershocks are also being felt in Washington. At least three members of Chicago's House delegation have publicly said they are considering running for mayor: Reps. Luis Gutierrez, a leader on immigration issues, Jesse Jackson Jr. and Mike Quigley -- all perhaps weighing the possibility of being in the minority in the next Congress.

And, of course, there's White House Chief of Staff Rahm Emanuel. The former DCCC chairman who seemed to be on track to be a future House speaker can't afford to be seen as being distracted by the lure of Chicago City Hall as the Democrats' House and Senate majorities are threatened. But with the filing deadline for the mayor's race on Nov. 22 -- barely three weeks after the midterm elections -- he'd have to be lining up support just as congressional races go into the final stretch.