This is a blog about the 2008 presidential race, so we don't usually weigh in on developments down the ballot. The retirement announcement today of Sen. John Warner, however, will reverberate in the presidential orbit. For one thing, there is a near universal consensus that Warner's retirement puts his seat in jeopardy for the Republicans.

Ex-Gov. Mark Warner, a once-upon-a-time presidential candidate, is probably going to run for the Democratic nomination. He is extremely popular; he will be heavily favored to win; his race will draw upon the same grassroots energies that excited the Democratic base in 2006. Having Warner on the ballot will help the Democratic presidential nominee in Virginia.

Both Mark Warner and Sen. James Webb are considered by the politigensia to be potential vice presidential picks this year. Needless to say, Warner would take himself out of consideration by running for Senate. Will Webb be more attractive, or less attractive, if as a running mate in Warner is on the ballot? It's not clear.