This is probably a good strategy since it (a) makes for good rabble rousing but (b) will never have to be followed up on.Exactly. Republicans are famous for this sort of thing; in the 1980s, they usually had half a dozen or so Constitutional amendments that they favored, whether it was school prayer, or abortion, or term limits.
Why do Republicans do that? One reason is something I've talked about before, the mixed incentives of Republicans when it comes to holding office. In normal political parties, everyone (activists, campaign professionals, formal party officials and staff, and candidates) have a strong incentive to win elections. That's not true in the current GOP, because many campaign professionals (and possibly some others within the party) are better off if the party loses. Glenn Beck sells more books with Dems in office. People poised to make money from exploiting outraged conservatives will find it easier to do with Barack Obama as president than with George W. Bush.
Demanding impossible things is one way to square the circle. If Republicans can win elections but still fail to enact their agenda because they don't have the votes to reach supermajorities (or to override a veto), then the money machine can keep churning.
That's what impeaching Bill Clinton was all about (and why I expect plenty of impeachment talk if Republicans do gain the House in 2010). A full repeal of health care reform is a perfect new Republican issue. I don't know that it will be a central issue of the 2010 or 2012 elections, but I do expect conservatives to keep pushing it for quite a while.