Obamacare has extended health insurance coverage to nearly 20 million Americans – but that has done little to shift the public's oppinion about the law.

According to a survey released Wednesday by the Pew Research Center, 54 percent of Americans disapprove of the 2010 Affordable Care Act compared with 44 percent who approve of the law. While approval showed a modest increase since the law's passage, disapproval has increased by 10 percentage points. The divide has also become more pronounced since July, when 48 percent of respondents said they approved of the law and 49 percent said they disapproved.

The survey was conducted April 12 to 19, among 2,008 adults. Respondents answered questions about the law's personal impacts as well as its expected effects going forward.

The findings showed 31 percent of respondents say the health care law has had a mostly negative effect on them and their families, while 23 percent say the result has been positive and 45 percent say they have seen little change. Pew noted that the percentage of respondents saying they have seen little change has declined in the last three years but that the law’s “personal impact” has consistently been more negative than positive in its polling.

Perception of the law was deeply divided along party lines. The survey found that 78 percent of Democrats approve, compared with only 9 percent of Republicans. Republican approval of the law had risen from 11 percent in February last year to 18 percent last July.

Republican views of Obamacare became more negative after the exchanges, or marketplaces, experienced technical glitches, making it difficult for Americans to purchase tax-subsidized insurance. Though the website has improved, opinions from Republicans have not, the survey shows.

Differences in opinion by race also were apparent. Whites disapprove of the law by a nearly 2-to-1 margin – 64 percent approve while 33 percent disapprove – and blacks overwhelmingly support it, showing an approval score of 83 percent. The majority of Latinos, 57 percent, also approve of the law.