Presidential debate, 3 p.m., ABC, CBS, NBC, Fox and PBS, plus C-SPAN and cable news networks. For once, an election has seized attention. Strong candidates bring sharply divided issues and (at the conventions) large TV viewership. This debate isn't expected to merely let candidates recite speeches. Moderator Jim Lehrer hopes to have a give-and-take conversation between John McCain and Barack Obama, discussing domestic issues.

OF NOTE

"20/20: Portrait of a President," 7 p.m., ABC. Here's the first half of Diane Sawyer's look at the lives of McCain and Obama. This hour views the early years; next Friday is a look at their families.

"The Mentalist," 7 p.m., CBS. If you missed this series debut on Tuesday, catch it now. The first few minutes are stark, sharp and (at times) funny; then things get serious.

"America's Toughest Jobs," 7 p.m., NBC. Most weeks, the producers are on familiar turf, visiting jobs they've also filmed on cable shows. Here's the exception - contestants distract the bull in a bullfighting ring.

"Gone Country" finale, 5 p.m., CMT (Oceanic Digital Channel 587). This show has been teaching country-music styles to actors (Lorenzo Lamas, Sean Young) and rock or pop singers (Jermaine Jackson, Sebastian Bach, Mikalah Gordon, Chris Kirkpatrick, Irene Cara). Tonight, contestants sing and a winner is named.

"Suite Life on Deck" debut, 8 p.m., Disney Channel. The "Suite Life" series moves the guys onto a passenger ship that doubles as a school. London, whose dad owns the ship, is appalled to share a room with a country girl.

Also: There are plenty of movies for debate-haters, led by the Oscar-winning "Million Dollar Baby" at 5 p.m. on AMC. At 9, Disney Channel has "Minutemen" and USA has "Sweet Home Alabama."