Updated

As President Obama’s signature health care law turns four years old, most people say they understand how the law will affect them -- and a majority continues to oppose it.  At the same time, the number favoring the law sits at its all-time high, according to the latest Fox News poll.

The new poll, released Thursday, finds 40 percent of voters favor the health care law, while 56 percent oppose it.  Views of the law have changed little over the last four years.  The number in favor has been as low as 36 percent (January 2014) and has reached the current high of 40 percent several times.  The number against the law has ranged from 49-59 percent.

Republican opposition (86 percent) to Obamacare is greater than Democratic support (71 percent).  Independents oppose the law by 60-34 percent.

Obama signed the Affordable Care Act into law on March 23, 2010.

Six in 10 feel like they have a “good understanding” of the law and how it will affect their family.  It’s still confusing for 38 percent of voters.

Those who have a good understanding of the law are more likely to favor it than those who don’t understand it (45 percent and 32 percent respectively).

Still, majorities of those who understand Obamacare (53 percent) and those who don’t (62 percent) oppose it.

One problem people have with the law is they think it is going to cost them money:  65 percent think Obamacare is making health insurance more expensive, while just 24 percent say insurance is becoming less expensive.  Even 42 percent of Democrats and 30 percent of those favoring the law say it is increasing insurance costs.

The poll also finds that by a two-to-one margin, voters say it is unfair for the government to require young people to buy insurance they either don’t want to don’t think they need in order to make the new system work: 32 percent think it is fair, while 64 percent disagree.

Even so, people under age 30 are more likely than seniors ages 65 and over to be in favor Obamacare (44 percent and 35 percent respectively).

Will the health care exchange system succeed?  Voters aren’t convinced it will, but are more optimistic now than they were a couple months ago.  The new poll finds 44 percent feel confident that enough people will sign up to make it successful, up from 38 percent who felt that way in December.  Still, a 53-percent majority doesn’t think that will happen.

Most people in favor of Obamacare think it will succeed (73 percent).  Most of those opposed to the law don’t think enough people will sign up to make it work (76 percent).

There have been nearly 40 major delays and administrative fixes to Obamacare. The poll asks if this information shows it would be better to go back to the system that was in place in 2009: by a 50-43 percent margin voters say yes, it does.

Perceptions of the law are almost identical to assessments of how Obama is handling the issue: 40 percent of voters approve of the job he is doing on health care, while a 57-percent majority disapproves.  That’s an improvement from earlier this month when he hit a record low of 36 percent approval on health care (March 2-4, 2014).

The Fox News poll is based on landline and cell phone interviews with 1,015 randomly chosen registered voters nationwide and was conducted under the joint direction of Anderson Robbins Research (D) and Shaw & Company Research (R) from March 23 to March 25, 2014.  It has a margin of sampling error of plus or minus three percentage points for the total sample.