Democrats oppose sending more troops by 50 percent to 36 percent, Republicans favor it by 73 percent to 18 percent and independents are divided, with 44 percent opposing an increase and 41 percent favoring one.

Gallup says one factor in the change of sentiment may have been the case put forward for an increase by the top commander in Afghanistan, Gen. Stanley McChrystal.

The public also seemed to side with National Security Adviser James Jones, who chided McChrystal on Sunday for making such a public case for his request. Jones said that such proposals should come privately to the president through the military chain of command; Americans agree with this by a 62 percent to 30 percent margin.

Similar to the findings of a Quinnipiac University poll this week, Americans believe by 80 percent to 15 percent that an important reason to stay in Afghanistan is to weaken the ability of terrorists to strike at the U.S., but a much smaller majority -- 51 percent to 41 percent -- say that building a stable government in Afghanistan is an important reason to stay.

Fifty-five percent say the U.S. is making progress in weakening terrorist capabilities in Afghanistan, compared to 37 percent who say it is not; 51 percent say progress is being made in keeping the Taliban from retaking control of the country, compared to 40 percent who disagree; but 57 percent say efforts to build a stable democratic government are not working, compared to 32 percent who see progress being made.