Experts — and even some Republicans — say a GOP-controlled Congress next year would have to struggle to erase nearly $1 trillion in health reform spending over 10 years with the flick of a pen. Key parts of the bill, like new Medicaid entitlements, would require free-standing legislation, not merely routine changes during the appropriations process.

The only way the GOP can really deal a mortal blow is by taking back the White House in 2013, these Republicans say — but, even then, the clock would be running out, with the law well into its fourth year of implementation and just a year away from when major benefits kick in.

So despite the long odds, Republicans are zeroing in on a nibble-around-the-edges strategy — a long-term, but so far loosely defined, campaign to choke off funding piece by piece and weaken the law to the point that lawmakers feel they have no other choice but walking away from it.