Interesting sidebar to this Fox News poll on support for Obamacare.

The number of Americans who oppose the law jumped to 59% - an all time high - while only 36% support it. GOP opposition remained constant, but among Democrats and independents, the law continues to lose favor:

ObamaCare skidded to an all-time low in the latest Fox News poll, but in a switch, it's Democrats who are driving down the already unpopular law. In June, 22 percent of Democrats were opposed to ObamaCare, which blends expansive new health-insurance regulations with a new welfare program. In the latest survey, that number rose to 30 percent, helping push overall opposition to a new high of 59 percent. (Just 36 percent overall supported the law.) While the number that is most encouraging to Republican hopes of taking control of the Senate is the sky-high 64 percent opposition to the law among independents, the spike in Democratic opposition promises to be very consequential.

[A survey by the Robert Wood Johnson Foundation finds less than 40 percent of uninsured adults will obtain coverage in 2014.]

Unchained - President Obama has been able to keep his health law lurching forward because Senate Democrats have held the line against Republican efforts to alter it. The GOP moves to shield consumers from intentional and unintentional consequences of the law are unacceptable to the president because they would, mostly by design, start the process of disassembling his signature legislation. One way to keep Senate Democrats from doing as Sen. Mary Landrieu, D-La., did and acting in their own interests by attacking ObamaCare is the threat of reprisal from the Democratic base. The president's permanent campaign organization can only credibly threaten vulnerable Democrats if there are enough liberal supporters of the law to make defection costly. But if the Democratic rank and file is increasingly opposed to the law, the political price for bucking the president goes down. And does one suppose Democratic opposition is higher or lower in states where Democrats are more conservative? A 30 percent national average might mean that only 10 percent are opposed in deep-blue New York but that half are opposed in Arkansas, North Carolina or Montana.

That last point has serious implications for senate races next November. Given that there is a lot of "strong" oppopsition to Obamacare - instead of "somewhat opposed" - a vulnerable Democrat in Arkansas like Senator Pryor might not be able to count on a solid base of Democratic supporters. The same holds true in other red states where Romney beat Obama.

It is not likely that growing opposition among rank and file Democrats will get so bad that a significant number of Democrats would vote for repeal. But the longer the law stays in place, the more unhappy voters become and the more the Democrats will suffer for their support.