The expansion of health insurance to more than 30 million Americans is easily the most concrete and sweeping way that health reform will effect individual citizens. That should make for a pretty easy, and compelling, Democratic talking point on the law: The Affordable Care Act will get the uninsured covered.

Turns out, that message has barely broken through -- even among the uninsured themselves. Fewer than a third of uninsured Americans think the health reform law will help them, according to a new Kaiser Family Foundation poll. Nearly half think it won’t do much of anything, as this chart shows.

Which is not to say Republicans are doing much better on the politics of the Affordable Care Act.

At the beginning of this year, any Republican mention of “repeal” was nearly always followed by “Obamacare.” But it has since drifted into the background, barely factoring into a new regulatory repeal push that House Republicans announced Monday. A memo outlining the strategy, sent out Monday by House Majority Leader Eric Cantor (R-Va.), includes just one paragraph on a grandfathering rule for health insurance plans that will become a target in the winter.

So while Republicans pivot away from a health repeal agenda, Democrats look to be struggling to explain what exactly the health reform law will do for Americans.

Another graph from the new Kaiser poll is particularly revealing on this point. It shows both Democratic and Republican voters drifting away from their party’s position on the health reform law, by nearly equal numbers. Here’s what that looks like:

Despite their best efforts, Republicans and Democrats see their bases gravitating away from them on health reform. Since March, when the law passed, the number of Republicans who have a favorable opinion has gone up by 9 points. Over that same time period, Democratic approval ratings fell by 10 points. Independent voters, all the while, stubbornly stayed in place, with nearly the same number favoring the law as did 18 months ago.

Both parties are running up against the same two challenges here. First, the health reform law is really complicated. Beyond “repeal and replace,” the law doesn’t lend itself easily to slogans that convey how, exactly, it works. This hurdle has been particularly vexing for Democrats, who have seen low support for the health reform law, despite its individual provisions polling really well.

Second, the reform law has barely come online yet. Aside from a few early-to-implement provisions that rolled out in 2010, the big parts of the law -- the health coverage expansion, insurance subsides and end of pre-existing conditions -- don’t start until 2014. As Kaiser Family Foundation president Drew Altman writes in a column today, it’s hard to get voters jazzed about an intangible law.

“People who are busy in their everyday lives (and who are being bombarded by a highly spun, confusing political debate about the ACA), will only understand what a complex law like this does when it is tangible for them,” he writes, “When they either get the benefits themselves, see family members and friends benefiting, or see news reports about how the law is working after it is implemented.”

Likewise, it’s hard to get Republican voters incensed about health reform when the law hasn’t done that much yet.

Both sides, it seems are losing the message war.