A message from Obama

We are now officially only days away from the election of a lifetime, and Democratic presidential candidate Barack Obama comes to prime time tonight with a half-hour paid political announcement that is expected to reach such a large audience that Fox was willing to rearrange its World Series schedule to open up some airtime for the candidate. (8 p.m., WBAL-Channel 11, WJZ-Channel 13, WBFF-Channel 45 and cable channel BET)

GIVE ME MORE POLITICS The Biography Channel, meanwhile, weighs in tonight with profiles of the two presidential candidates: John McCain: American Maverick and Barack Obama. (9 p.m. and 10 p.m., Biography)

REMEMBERING BERNSTEIN He was a pretty political guy in his own right, but if you want a break from pure politics tonight, you might consider Carnegie Hall Opening Night 2008: A Celebration of Leonard Bernstein. The San Francisco Symphony and some of the biggest stars from the world of music celebrate Bernstein's music in this Great Performances production. (9 p.m., MPT-Channels 22 and 67) *** 1/2 .

LATE-NIGHT GUESTS Actor Alec Baldwin visits the Late Show with David Letterman (11:35 p.m., CBS). Actress Sarah Silverman appears on The Tonight Show with Jay Leno (11:35 p.m., NBC).

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