Republicans are still trying to undo the Affordable Care Act.

Since health-care reform was signed into law more than three years ago, House Republicans have held some 40 votes to repeal the ACA, and are now talking about either shutting down the government or holding the debt ceiling hostage to, they hope, force President Obama to scrap his signature legislative achievement.

Such strategies may well be quite popular among the conservative base. But should the GOP actually go through with one of those plans, it could turn other voters against the party and, as a result, cost them dearly come 2014. Indeed, that's what at least one GOP lawmaker is now warning his colleagues.

"Potentially there will be a collapse of will to keep the government shut down because soldiers are not getting paid, and all this other stuff's happening, and we turn around and lose 10 to 20 seats in 2014," Rep. Adam Kinzinger (R-Ill.) said Wednesday at an event back in his home state. "And whether we win the battle or not, we've lost the war because Nancy Pelosi's speaker of the House."

Now, it's unlikely that the GOP will lose the House. With a 234-201 advantage, Republicans would have to cough up an awful lot of seats in 2014 for Pelosi to grab the gavel. But as Kinzinger warned, Republicans have to "ensure that in the future we can repeal this law without bringing down the American economy or bringing down the Republican majority in the House."

A government shutdown would force all non-essential spending to come to a halt this fall until lawmakers pass a new budget — a continuing resolution, in D.C. speak. A refusal to raise the debt ceiling, on the other hand, would have an uncertain, though potentially ruinous, impact on the U.S. economy. In that way, the GOP's reported idea to shift the defunding debate from the budget to the debt ceiling has raised the stakes in an already high-stakes battle.

The defunding effort is, for now, largely contained to the conservative and Tea Party-aligned corner of the Republican Party. And those spearheading the effort, perhaps unsurprisingly, think such a standoff would have no negative impact on the GOP.

The conservative group Heritage Action this week touted a poll it commissioned of 10 "swing" districts which purportedly showed voters favoring a government shutdown, and saying they would be more likely to blame Democrats should one occur.

From Heritage Action:

There is no present evidence that a move to defund ObamaCare, and the potential of a partial government shutdown, would harm Republican prospects of holding the House majority. In fact, the very same voters who are critical to keeping the majority — independents in potentially competitive districts — hold highly negative views on ObamaCare and strongly favor a slowdown in implementation or outright repeal of the law. [Heritage]

However, that poll has been widely criticized for having a heavily Republican-leaning sample and for containing some very leading questions. After a series of questions implying that the ACA will be bad for health care on the whole, the survey frames a government shutdown in the rosiest of possible terms:

In order to get President Obama to agree to at least have a "time out" on implementing the health-care law and its full effects, would you approve or disapprove of a temporary slowdown in non-essential federal government operations, which still left all essential government services running? [Heritage]

Even the Washington Post's conservative columnist Jennifer Rubin thinks that poll is "junk" and "terribly dishonest."

Newt Gingrich, who ran the House during the 1995 government shutdown, cautioned his fellow Republicans this week against becoming an opposition party with no alternative message of their own.

"We need to get away from this, 'I'm against ObamaCare,' and then stop — and that's all you have to say," he said.

There is some reason to believe the party will not go through with the threats in the end, that when push comes to shove the party leadership will walk away from the cliff rather than risk the political consequences of hurtling off of it. If they don't, though, the length and severity of a government shutdown, or the fallout from a debt ceiling default, will dictate how strong of a backlash the party faces.