Americans are nearly split on support for a timetable for withdrawal of U.S. troops from Iraq, according to an ABC-Washington Post poll out Tuesday, while a new Quinnipiac poll shows just the opposite.

An ABC-Washington Post poll of 1,119 adults shows voters divided 50-49 percent for a timetable for withdrawal. However, the Quinnipiac poll of 1,725 likely voters finds 51-43 percent against a timetable.

In the Quinnipiac poll, Democrats and Republicans fell predictably for and against withdrawal, respectively, and independents tilt away from a fixed date of withdrawal, 56 to 40 percent.

"The overall numbers show a big partisan split on the war in Iraq. Almost three-fourths of Republicans think it was the right thing to do. Democratic denunciation is overwhelming," director of the Quinnipiac University Polling Institute Maurice Carroll said in a statement accompanying the poll.

The ABC-Washington Post poll also shows independents' tilt away from timetables, 53 to 47 percent.

Those polled by ABC-Washington Post said John McCain is clearer than Barack Obama on his intentions for withdrawal from Iraq, 60-56 percent. The poll also showed that McCain is considered a stronger commander in chief by 72 to 48 percent, even capturing most Democrats' support.

The progress of the wars in Afghanistan and Iraq seem to reflect changing attitudes.

The ABC-Washington Post poll shows 51 percent believe the war in Afghanistan is unsuccessful, up from 24 percent in 2002. Forty-four percent say U.S. efforts in Afghanistan are successful, down from 70 percent, the poll shows.

In the broader War on Terror, a majority thinks Afghanistan is more important to the larger terror-fighting effort than the Iraq war.

The ABC-Washington Post poll also found that a 51 percent majority believes the U.S. must win in Afghanistan for the War on Terror to be a success. Sixty percent responded that the U.S. War on Terror could be a success without winning the war in Iraq.

The majority of Democrats and independents say the Iraq war was not worth fighting. Independents side more with Republicans on Afghanistan in saying it was worth the fight and linked to the defeat of terrorism.

The Quinnipiac poll gave Barack Obama a 50 to 41 percent lead over McCain. The overwhelming support of black voters and a 19-point lead among women explains this 9-point deficit for McCain.

Obama leads by 32 points among 18-34 year olds. McCain is up among those aged 55 and older.

Independent voters split 44 to 44 percent for the candidates.

"As is usually the case, the outcome probably will be decided in the middle, among the independent voters, who are evenly split at this point," Carroll said.

The ABC-Washington Post poll has a margin of error of 3 points. The Quinnipiac poll's margin of error is 2.4 points.