Rep. Xavier Becerra (D-Calif.). (Andrew Harrer/Bloomberg News)

The news that Rep. Xavier Becerra will leave Congress to become California's attorney general takes another potential Democratic leader off the board in Washington and further highlights the remarkable thinness of the party's bench of rising stars in the nation's capital.

Becerra announced Thursday morning that he had accepted the appointment — offered by Gov. Jerry Brown (D) -- to fill the vacancy created by Kamala Harris's Senate victory 22 days ago. “Governor Brown has presented me with an opportunity I cannot refuse,” Becerra said in a statement confirming the move. 

For Becerra, it makes sense. His stock in Washington had fallen somewhat in recent months and with Rep. Nancy Pelosi's reelection as minority leader on Wednesday — and the retention of the two other top leaders for House Democrats — it would be at least two more years before Becerra could move up the leadership ladder at all. Now he will be positioned to run for a statewide office (governor in 2022 or 2026, Senate in 2018) or be plucked by the next Democratic president as a Cabinet pick.

For the Democratic Party in Washington, Becerra's decision is part of a broader, troubling trend: Young, ambitious lawmakers either falling by the wayside or giving up on the House entirely. Consider the fates of the handful of Democratic legislators seen, as recently as a few years ago, as the next generation of House speakers-to-be:

  • Xavier Becerra (Calif.): Appointed California attorney general
  • Chris Van Hollen (Md.): Won an open Senate seat in 2016
  • Steve Israel (N.Y.): Retiring from Congress this year
  • Debbie Wasserman Schultz (Fla.): Removed as chair of the Democratic National Committee

It's remarkable. An entire generation of Democratic leaders in Washington has been washed away — and the generation younger than the Van Hollens and Israels of the world look to be too young right now to step up and fill the leadership vacuum.

There are lots of reasons for this lost generation — some of them unique to the individuals. But, the common thread that connects them all is that Pelosi along with Reps. Steny H. Hoyer (Md.) and James E. Clyburn (S.C) have had a death grip on the party's top leadership slots for a very long time. While that's great if you are — or work for — Pelosi, Hoyer or Clyburn, it's bad if you are young, ambitious and looking to move up the political chain in Washington.

It's hard to disconnect the long run of power by these three House Democrats from the atrophying of the caucus below them. Consider it this way: A legendary basketball coach just keeps coming back for the next season — then the next season after that. The guy is a legend. No one — not the boosters, not the athletic director, not anyone — is going to push him out. But what usually happens in those situations? The coach loses a bit of his edge even as his top assistants, who have served loyally but are ready for a chance at the big job, leave the program for other opportunities. When the legendary coach finally does call it quits, the program is typically in bad shape — and there's no natural heir waiting in the wings to rebuild it.

That's what appears to be happening among House Democrats. No one in their right mind would question the historic nature of Pelosi's run in leadership or her remarkable effectiveness in keeping her caucus together. But, as rising stars continue to walk away from the House, the party needs to ask itself whether it's setting itself up for a massive leadership void down the road.