They know it is an exercise in futility, because even if (for some reason) the House Republicans manage to pass a vote to repeal Obamacare, the Senate won't take it up OR pass it, and even if THAT happened, Obama will never sign the repeal into law.

So it's a symbolic thing.

That's okay.  Symbolism has its place.  But this is ridiculous.  They want to be able to go home and say, "I voted 17 times against Obamacare" or (for members who have been there longer), "I voted 43 times against Obamacare."

That makes it dumb.

And unfortunately, these repeal votes might become a stain.  Why?  Read this from the New York Times:

The repeal vote, which is likely to occur Thursday, will be at least the 43rd day since Republicans took over the House that they have devoted time to voting on the issue.

 To put that in perspective, they have held votes on only 281 days since taking power in January 2011. (The House and Senate have pretty light legislative loads these days, typically voting only three or four days a week.)

 That means that since 2011, Republicans have spent no less than 15 percent of their time on the House floor on repeal in some way.

That's right.  With a dicey economy, terrorism, etc., the Republicans spent almost one-fifth of their time on the House floor voting for repeal.

Waste of time.  Waste of House seats.

UPDATE: Last year, CBS News calculated that the number of hours spent on 33 repeal votes — then roughly 80 hours, or two full work weeks — cost taxpayers an estimated $48 million. Since then, Republicans have held three more votes (another $4.5 million) to repeal ALL of Obamacare and will add another $1.5 million with their latest.