I think DrewM is right on two key points. First, too many of the Republicans in Congress talk of legislative minutia that is of interest only to insiders. As a result, they miss their chance to convince voters to support them.
Why It's Called "The Stupid Party": GOP Turns Fight Against The Horrors Of ObamaCare Into A Process Story
You know why the GOP loses a lot? Because it deserves to.
Yesterday a bunch of Republican Senators went around to the various Sunday shows and instead of talking about why it's imperative ObamaCare be repealed because of the damage it's doing, they decided to make it about how much they hate Ted Cruz. Some Republicans went as far as to offer Fox News Sunday Host Chris Wallace what he termed, "opposition research" on Cruz.
Then there is the cowardice factor:
The same thing happened when Rand Paul filibustered over the issue of Presidential authority to order drone strikes anywhere against anyone. Even non-libertarians had to admire his willingness to take on a tough issue.
You know why Cruz is so popular? Because he's actually fighting. Maybe it's a losing fight, maybe it's a fight to raise money (though let's not pretend he's the only one doing that) or to raise his popularity (the sight of professional politicians accusing anyone of self-aggrandizement is too precious) but at least he's fighting.
That said, I think "fighting" conservatives are still fighting the last war in the effort to defund Obamacare. Their opposition is couched in ideological language and American's are not very ideological. Plus, our ideology does not enjoy the support it once did.
The usual mantra of "No socialism, Free Enterprise!" just seems inadequate in the face of the current economic realities.
Key fact number one. As Obama moves toward "socialism", he does so at the behest of the "capitalists". It is not as if he is sending paramilitary gangs to take over successful, profitable businesses. Obama, like Bush before him, is compelled to act because the capitalists screwed the pooch, crapped the bed, and then muttered "maybe my bad" when their recklessness sent the financial system off a cliff.
The broad public knows this, and that makes it hard to win them over with cheap slogans about socialist bogeymen.