"The 2009 races are not a referendum on Obama."
That's what everyone's saying. And it's false. Each election hinges on something different, but where there's a common thread to most of the races, it's out-party, conservative enthusiasm, which is inversely correlated to how well Obama is perceived to be leading the country.
"The 2009 races are mostly a referendum on Obama."
Not true. Virginia rejected a Republican attorney general a few months after September 11, 2001; no one suggested that George W. Bush was to blame. Jon Corzine is much less popular in New Jersey than Obama. He's been the guy on watch as New Jersey's economy tanked. These races are mostly a referendum on the ability of conservatives to turn out their base voters in off-year elections at a time when Democrats are nervous and the economy is in tatters. Nothing concentrates the mind of the opposition like economic discontent, and that force usually benefits the party out of power.
"The 2009 races don't mean much for 2010."
Wrong. They set perceptions among candidates, strategists, and the media. They'll determine whether Democrats believe they'll be punished or rewarded for favoring an Obama-identified health care plan. They'll set the tone of (particularly) GOP primaries in House districts in early 2010. They'll contribute to the environment that 2010 candidates find themselves in. We won't know everything, but we'll get a sense of the depth of anti-establishment sentiment, the ability of conservatives to turnout voters in critical races, the skittishness of Democrats, and the way the parties in power respond to the developments. The 2009 races won't tell us whether Republicans will take back the House and Senate in 2010 -- still unlikely, in my opinion -- but they'll help Republicans and Democrats figure out how to run.
"NY-23 is all about frustration with Washington."
Which parts of Washington? The race became famous because it was hijacked by conservative activists who wanted to send a message to their own party: you've taken us for granted, and you're insulting us by running liberals in conservative districts. Doug Hoffman allowed this hijacking because it brought millions to his campaign coffers (most of which came from outside the district) and it freed him to focus on building a plurality of high turnout conservative voters. It's doubtful that conservatives inside the district care one way or another about the NRCC. If they're angry at a party organ, it's Republicans in Albany who denied them a primary and a voice.
"Republicans are in danger of marginalizing themselves."
Too early to tell. Democrats assume that Republicans can't build a majority coalition on the backs of economic discontent and the fused cultural/political anxieties of white males and conservative independents. What they can do is bottle up legislation in Washington to such a degree that it seems as if the majority can't do anything...or scares the majority into pandering to the left in order to balance the partisan energies. A Palin-Beck Republican Party as the White House is given to calling it, probably can't win a presidential election. But they can force primaries in marginal House districts and they can magnify the voices of those who adhere to conservative, anti-establishment populism. There are two parties in this country. Until there's a third choice, the party out of power will tend to benefit from anomie, dissatisfaction, malaise, and anger. At the very least, the conversation in this country will shift in the direction of those who are making the most noise. That's bad for Democrats. Just because elites don't think the American people will tolerate anti-government, culturally anti-modernist conservative candidates, doesn't mean that the American people won't tolerate them.
"Voter anger is misplaced. It's not Obama's fault."
The anger is justified; the blame can only flow in his direction. It doesn't matter whether President Obama's economic interventions saved the economy. All that matters is that the banks and the financiers and the car companies and the big corporations and the elites seem to be suffering less than the average American. Technical arguments about economic policy just don't translate well in politics: it doesn't matter IF the president can't create jobs fast enough, it matters that he's not doing so. He's going to get to the blame regardless. The basic vacuum energy of politics is economic dissatisfaction.
"Democrats are more naturally populist."
Maybe in ideology, but not in practice. In fact, nothing endures your marginalization from the professional elite of the Democratic Party than an association with populism. The big conceit of the Democratic era is to find ways of spending more to stimulate the economy while making it look like Democrats are committed to "fiscal discipline," whatever that means. Neither the president, nor the speaker of the House, nor the majority leaders of the House and Senate have the inclination, the ability, or the stomach for advancing a populist arguments. Republicans like to use populist arguments to advance corporatist policies. Democrats find this unfair, but the reason they're in the majority now is because they've built a policy coalition that is unsuited to populism and more suited to centrist policies (as the health care reform bill really is).