Some moderate Democrats are proposing to change the individual mandate, the least popular element of the Affordable Care Act. Politico's story is entitled, "A new Dem threat to health care law." Greg Sargent frets:

If these Dems think this is going to insulate them from GOP attacks, they're kidding themselves: Last night, the NRSC sent out a release blasting McCaskill, asking why she voted for "Obamacare" in the first place if she thinks the mandate is such a bad idea. All they're succeeding in doing is undermining one of the Democratic Party's signature domestic accomplishments.

I think this totally misses what's going on here. The individual mandate is a tool to prevent people from free riding on the health insurance market. It's not the only tool to accomplish that. You can change it without threatening health care. Indeed, liberal Democrat Peter DeFazio has already proposed to replace the mandate with a plan, created by liberal health care wonk Paul Starr, to deny those who forego insurance the ability to reap the benefits of the Affordable Care Act.

Now, the moderate Democrats have not yet unveiled their proposal. But I can promise you this: it will not neuter the individual mandate and replace it with an ineffective alternative that guts the health insurance market. Why not? Because insurance companies don't want that, and if there's one thing that characterizes moderate Democrats, it's a powerful aversion to upsetting the insurance industry. The insurers are fine with the Affordable Care Act. They're fine with repealing the Affordable Care Act and going back to denying coverage to sick people. They're not fine with keeping the requirement that they cover sick people but letting healthy people stay out of the system until they get sick.

As it happens, one person who grasps what's happening, in his reptilian manner, is former Rumsfeld speechwriter Marc Thiessen, who warns Republicans not to cooperate with any attempts to modify the Affordable Care Act:

Last week, [Republicans] helped Democrats pass legislation repealing the provision Obama mentioned - a mandate that businesses file "1099" reports to IRS for all transactions of more than $600 in a given year. This provision had small businesses across the country up in arms. But instead of harnessing that anger to push for full repeal, Republicans instead helped Democrats lift this source of pressure from the business community.
Each individual proposal will seem entirely reasonable and an opportunity for bipartisan cooperation. But if Republicans go along, before they know it they will find that they have been drawn into a strategy of "fix and save" instead of "repeal and replace." ...
As more "fixes" like the 1099 repeal are adopted, the president and Democratic leaders will portray themselves as the reasonable ones who have acknowledged flaws in their law and are working to address them in bipartisan manner. Meanwhile Republicans who continue to push for full repeal will be portrayed as strident hard-liners who care more about delivering a political blow to the president than helping Americans get better health care. 

Now, Democrats will portray themselves as reasonable people looking to improve the system, and Republicans will be seen as ideological hard-liners, because that in fact is the reality. But if you share Theissen's premises -- the jihad against the ACA must never be abandoned, and anything that improves the health care system is bad for the GOP -- then the drive to change the Affordable Care Act is terrible for Republicans. I predict they follow Thiessen's advice. Indeed, that notion is already afoot, as the Politico story shows:

Some in GOP circles fear that by teaming up with Democratic moderates, they could give these Democrats bipartisan cover that would help them in 2012. 
Some Republicans are quietly warning colleagues not to work with vulnerable Democrats in the first place. This comes after Sen. Bob Corker (R-Tenn.) teamed up with McCaskill to back a proposal that would dramatically cut spending over the next decade and Sen. Mike Johanns (R-Neb.) worked with Manchin to repeal a small-business reporting provision in the health care law.

If you think about it, this is exactly the strategy Republicans pursued in 2009-2010. If a few of them put something on the table -- and many moderate Democrats were ready, especially after the Massachusetts election, to accept the tiniest incremental scrap -- they could have persuaded Democrats to abandon the comprehensive plan they passed. Instead they calculated that withholding bipartisan support would maximize their advantage in the elections. I expect them to pursue the same strategy again.