a White House aide says that President Barack Obama will veto any bill limiting the EPA's ability to regulate greenhouse gas emissions.

Instead the Republicans have, by dangling one after another sorta-anti-abortion nominee after another over the last 30 years, managed to build those activists into the base of their party (though some might argue even those activists are out of touch - to the left - of today's true Tea Party base).  

Said another way, hanging a carrot in front of a horse works only so long as the horse can't get the carrot but it continues to dangle.  Once the horse gets and eats the carrot, that carrot no longer works and the driver has to find a new one lest the lazy horse take a break.  That's how all pols treat their base.  Keeping an issue alive by not resolving it is often more politically beneficial, in terms of activist involvement and fervor, than actually resolvng it.

Me, I still think Ronnie was guided by his PR and Hollywood friends and nominated O'Connor on July 7, 1981, about 6 weeks before this really bad movie came out (August 21, 1981).  Not that the Reagan White House wouldn't know what was in production in Hollywood or anything.  But, also, it bears remembering Reagan had promised in his campaign to nominate the first woman to the S.Ct.

Of course, even fulfilled campaign promises can have deeply ironic twists to the politicians' bases who watch for fulfillment of such promises.

Also of course, though, is the ability (and some might say duty) of activists to make the pols, who are playing them by dangling the carrot just out of reach, come through.  The best way for a base to force the pols' hands and give them what they have been fighting for is to do what many of the Dem activists have been doing or threatening to do to Obama:  Sit on their hands and do nothing.