>Every Republican voted against it. At no point did Republicans in Congress try to improve any of its manifest flaws

David Frum argued against this and got booted from polite conservative company for his troubles. The Obama administration inserted poison pills into the bill, like some of the impositions on small businesses, as bargaining chips they could give up to Republicans in exchange for their support, but he seriously misjudged the Republican mood.

Fact is, in the middle of a massive recession when the government had just rammed through a really ugly trillion dollar bailout and the deficit was going through the roof, no conservative was going to vote for a massive new entitlement program. They wouldn't vote for it now, either.

You also have to understand how immensely unpopular Obamacare is with the Republican base, which has very little to do with Fox News and everything to do with how it's a massive wealth transfer from working taxpayers to the nonworking poor. Obama likes to crow about giving 20M people health coverage, but think of what that means: 300M already had it. And for those 300M, their health care coverage got worse and more expensive.

And Obama's "Elections have consequences. I won." line to Eric Cantor might, in retrospect, not have been the ideal way to get Republicans on side. Just throwing that one out there.

>Romney ran for president on a platform that his healthcare plan was a good idea when he did it but a bad idea when Obama did it.

Which was obvious bollocks, and one of the reasons he lost--there was absolutely no appetite for Romney among the Republican base. He was the Republican's Hillary Clinton.

>To liberal ears, it's really hard to explain how this was a principled stand against wacky liberal ideas run amok

Conservatives believe government is generally terrible at everything. They think the health care system needs less government, not more. Your default position when it comes to "will conservatives support x policy proposal" should be, "if it shrinks the government then yes, otherwise no".

The US currently has around $100T, with a 'T', in unfunded liabilities in Medicare, Medicaid, and Social Security. That gap is going to close one way or the other, either through increased taxes, decreased spending, or a sovereign debt crisis. Adding another massive chunk to that is a very bad idea that conservatives simply do not like. Paul Ryan isn't trying to cut Medicaid and Medicare and Social Security because he's a nasty man who hates poor people, he's doing it because the US simply cannot afford those programs and the only way to pay for them would be to massively raise taxes. If you're okay with that, vote Democrat.

>simply an attempt to regain power by obstructing even previously-bipartisan ideas, even at the cost of damaging the country, to ensure that the other side couldn't take credit.

There's a real divide in the GOP between the line-in-the-sand types and the responsible government types. You've got people like Boehner, who thought it was necessary to compromise with Obama on some things, and people like Cruz, who thought it was vital to take a stand and ensure the government did not continue to grow, even at the cost of shutting it down. While electoral politics certainly play some role in that, it really is driven by ideology. Ted Cruz, whatever else you might say about him, is not a flap-in-the-wind sort of guy. He's a true believer. Ditto Ryan.