First, some key statistics from Open Left:
In 2008, according to exit polls, 89% self-identified liberals voted for President Obama. Over the past four weeks, according to Gallup, President Obama's approval rating among self-identified liberals has averaged 74%. That is a decline of 15 points.
In 2008, according to exit polls, 60% of self-identified moderates voted for President Obama. Over the past four weeks, according to Gallup, President Obama's approval rating among self-identified moderates has averaged 54%. That is a decline of 6 points.
In 2008, according to exit polls, 20% of self-identified conservatives voted for President Obama. Over the past four weeks, according to Gallup, President Obama's approval rating has averaged 24% among self-identified conservatives. That is an increase of 4 points.
President Obama got 53 percent of the vote in November 2008. His approval ratings are now about seven points lower, meaning that around fourteen percent of those who voted for Barack Obama are now claiming to "disapprove" of the President's performance today (because 14 percent of 50 percent is 7 percent of the whole sample).
Some of that deficit has come from a drop in support among moderates. A lot of that deficit has come from discontent among liberals and progressives.
That doesn't mean Democrats are not in trouble in the midterms: because young people and poor people often think midterms are too unimportant to vote in them, or they're too busy with other issues in their lives, much of the Democratic base is gone, which is always a major boost to Republicans. Democrats tend to do poorly in midterm elections, especially when their party is in charge.
But it does mean that, things looking as they are now, the President will easily be able to shore up his support in 2008 against a Republican opponent. Progressives who think Obama hasn't done enough for them aren't going to turn and vote for Newt Gingrich or Mitt Romney.
Of course, the numbers that Gallup found and Open Left reported are a bit misleading when some "moderates" have switched to defining themselves as conservative, and some "liberals" have switched to defining themselves as moderate, since the election. As I have pointed out many times before, Americans are devils' advocates and lovers of balance, and position themselves in contrast to whatever they see as the most powerful party. Still, one thing that is definitely true is that the numbers for Obama are not as bad as they seem.
Anti-Obama conservatives are numerous, are certainly loud, and they have grown in prominence and attention-getting ability since the 2008 election. But they aren't more numerous than they were in 2008. Ask a few of Barack Obama's most vehement opponents who they voted for in 2008: it almost certainly wasn't Barack Obama, and the president will do just fine if only the people who voted for him in 2008 vote for him again in 2012. All things considered, when he comes head-to-head with a Republican candidate he will still have their support.