A new poll done for Republican members of Congress has found huge public opposition, and solid opposition among Republicans, to the idea of shutting down the government over the issue of funding Obamacare.

In a national survey of 1,000 registered voters done July 31 and August 1, the question, from pollster David Winston, said, “Some members of Congress have proposed shutting down the government as a way to defund the president’s health care law” and asked respondents whether they favored or opposed that plan.

Overall, 71 percent of those surveyed opposed a shutdown, while 23 percent favored a shutdown. Among Republicans, 53 percent opposed, versus 37 percent who favored.

Winston found a huge gender gap among Republicans. Republican men favored a shutdown by a narrow 48 percent to 44 percent margin. But Republican women opposed it by an enormous 61 percent to 29 percent margin.

Among Republicans who called themselves conservative, those who said they are very conservative favored shutdown by 63 percent to 27 percent, while those who said they are somewhat conservative opposed shutdown by 62 percent to 31 percent. Overall, Republicans who call themselves conservative were evenly split on the issue, 46 percent to 46 percent.

Conservative Republicans make up about 19 percent of the entire electorate. Of that number about nine percent call themselves very conservative, while ten percent say they are somewhat conservative. What the poll suggests is that even that conservative cohort is deeply split on the defunding initiative.

Winston also did a generic ballot test. Among people who say at this point that they plan to vote for the Republican candidate in 2014 — regardless of who it is — 51 percent said they opposed a shutdown, while 40 percent favored it. “What has to be concerning here is the fact that more than half the people who are presently voting for a Republican oppose this idea,” Winston told me. “If you’re concerned about what it might look like in terms of a general election, if half the voters who say they are going to vote for a Republican candidate oppose this, then you are creating a conflict for them to vote for a Republican candidate.”

Proponents of defunding will likely challenge the premise of Winston’s question, arguing that defunders are not proposing to shut down the government but rather want to fund all government operations other than Obamacare. But there is no doubt defunding advocates anticipate a possible shutdown; their hope is to persuade the public to blame President Obama, and not Republicans, for it. The new numbers suggest they will have a lot of persuading to do.