More Americans think Supreme Court justices will be acting mainly on their partisan political views than on a neutral reading of the law when they decide the constitutionality of President Obama’s health-care law, according to a new Washington Post-ABC News poll.

Half of the public expects the justices to rule mainly based on their “partisan political views,” while fewer, 40 percent, expect their decisions to be rooted primarily “on the basis of the law.” The rest say both equally or do not have an opinion.

The court held a historic three days of oral arguments on the Patient Protection and Affordable Care Act last month, and its ruling probably will come just before the court adjourns at the end of June. The poll shows little enthusiasm for the Obama administration’s position that the law, passed by the Democratic Congress in 2010, should be upheld in full.

Only a quarter of Americans choose that as the desired outcome. Thirty-eight percent would like the entire law thrown out; 29 percent would like the court to strike the requirement that individuals obtain health insurance and to keep the rest of the law.

Only 39 percent of Americans support the health-care overhaul in general, the lowest percentage since the Post-ABC poll began asking the question.

The public’s perception of the court is closely tied to partisan and ideological leanings. Almost twice as many conservative Republicans think the court will decide on the basis of the law rather than politics, 58 to 33 percent. Liberal Democrats are more skeptical, saying by an equally wide margin that the court will put politics first.

Just over half of political independents think the court will base its ruling on partisan predispositions. This includes similar numbers of independents who support and oppose the health law.

Only about half of Democrats want the entire law upheld. Nearly two-thirds of Republicans want all of it thrown out.

The court’s ideological and partisan divide is pronounced. For the first time in generations, the court’s five conservatives were nominated by Republican presidents, while the four-member liberal bloc was nominated by Democratic presidents.

The poll was conducted April 5 to 8 among a random national sample of 1,103 adults. Results from the full survey have a margin of sampling error of plus or minus 3.5 percentage points.

Polling director Jon Cohen and polling manager Peyton M. Craighill contributed to this report.