Republican Sarah Palin will square off against Democrat Joe Biden tonight in the most anticipated vice presidential debate in years.
The election's sole VP debate will be televised live from 9 to 10:30 p.m. at Washington University in St. Louis.
Palin energized the John McCain campaign in August as McCain's surprise vice presidential nominee, but the campaign has since slipped in national and state polls – in part because of shaky Palin performances in TV interviews with ABC's Charles Gibson and CBS's Katie Couric.
The debate offers Palin a chance to regain the voice that electrified Republicans, some of whom are now publicly questioning her fitness for the vice presidency. Campaign officials have hinted at a more aggressive Palin tonight.
Biden, whose recent campaign gaffes have been grist for GOP supporters and bloggers, will look to avoid mistakes that could again swing momentum. Biden is expected to tread lightly with Palin, instead focusing his attention on McCain's policies.