As Afghanistan holds presidential elections, a new poll shows that a majority of Americans oppose the war — and there’s a stark difference on party lines.

A majority of Americans now see the war in Afghanistan as not worth fighting, and just a quarter say more U.S. troops should be sent to the country, according to a new Washington Post-ABC News poll.

Most have confidence in the ability of the United States to meet its primary goals of defeating the Taliban, facilitating economic development, and molding an honest and effective Afghan government, but few say Thursday’s elections there are likely to produce such a government.

When it comes to the baseline question, 42 percent of Americans say the United States is winning in Afghanistan; about as many, 36 percent, say it is losing. …

Overall, seven in 10 Democrats say the war has not been worth its costs, and fewer than one in five support an increase in troop levels.

Republicans (70 percent say it is worth fighting) and conservatives (58 percent) remain the war’s strongest backers, and the issue provides a rare point of GOP support for Obama’s policies. A narrow majority of conservatives approve of the president’s handling of the war (52 percent), as do more than four in 10 Republicans (43 percent).

Among all adults, 51 percent now say the war is not worth fighting, up six percentage points since last month and 10 since March. Less than half, 47 percent, say the war is worth its costs. Those strongly opposed (41 percent) outweigh strong proponents (31 percent).