For months, conservatives have used the unpopularity of health care reform to argue against its passage by Congress. If the American people oppose it, they argued, Congress should respect that. So it's a curious turn of events that American public opinion may have now shifted in favor of health care reform. A joint Gallup-USA Today poll conducted immediately after the bill passed reports that just over half of respondants support the legislation and that exactly half are "pleased" or "enthusiastic" about it. Why do Americans now support the reforms they opposed only as recently as two weeks ago?

• Nothing Succeeds Like Success  The Washington Post's Ezra Klein writes, "Voters like success, the media covers winners more positively than losers, and people take their cues from outcomes."

• This Has Always Been The Case  The New York Times' Paul Krugman grunts, "Actually, it’s not clear whether public opinion has changed all that much: a substantial fraction of those who disapproved of the reform did so because it didn’t go far enough."

• Will Settle Into 'Generic Partisan Controversy'  Liberal blogger Matthew Yglesias predicts, "Over the next few months, we’ll see that this is a pretty generic partisan controversy on an issue where Democrats are generally more trusted. The idea that running around the country denouncing the Affordable Care Act as the second coming of Joseph Stalin and promising to repeal it at the soonest possible opportunity is going to be a big political winner is silly."

• The Media Did This  The Economist explains, "The American people did not have clearly formed opinions on the content of this bill. They had vague opinions on the bill that were heavily influenced by the media narrative surrounding the development and legislative process of the bill's progress. Over the weekend, that narrative went from one of quagmire, self-recrimination among Democrats and dire warnings among Republicans, to one of accomplishment, celebrations among Democrats, and dire warnings among Republicans".

• People Want More Reform  Talking Points Memo's Evan McMorris-Santoro thinks the poll suggests Americans want the Democrats to keep going on reform, which is "good news for Democrats worried about their election chances." 48% of respondants "called the bill 'a good first step' and should actually be followed by more reform efforts. Should the poll live up to the paper's preview of it, it would be something of a coup for Democrats."

• Support Will Continue Rising  The Washington Monthly's Steve Benen foresees "the Republican nightmare coming to fruition -- the country gets a better system, Democrats get a victory, the president looks like a hero, and the country is pleased with the results." He writes, "As more of the country learns that GOP scare tactics were baseless, and hears about the new benefits that kick in this year, the polls will likely improve further."

• People Fatigued on Health Care  Politics Daily's David Corn sighs, "my hunch is that a lot of Americans are also exhausted by the reform tussle and may want to move on. Keeping this fight alive could serve the Republicans well among their Tea Party base, but it might turn off independent voters and others who wonder if the GOP has become a party of sore losers, who prefer re-fighting a lost battle to focusing on revving up the economy."

• This Is Just One Poll, People  Stats wonk Nate Silver with the reality check. "But -- hold your horses. This is just one poll, and even if the bounce is real, it may very well evaporate," he writes. "It's not unusual for a candidate or cause to see its numbers improve after it wins a couple of high-stakes news cycles -- but the bounce usually evaporates after a couple of weeks."

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