I think that Matthew Ygelsias may be overstating President Obama's political strength vs. Congress, as supposedly evidenced by this chart:
If I’m in White House Legislative Affairs and I’m talking to a nervous member of congress, I’m showing them that chart and arguing that the progressive president is more popular than the somewhat dawdling congressional Democrats and way more popular than the obstructionist Republicans.
The problem for Obama is that people don't vote for "congressional Democrats" or "congressional Republicans," they vote for individual candidates, usually incumbents. I'm sure that every member of Congress would claim to be more popular back home than his or her own party, and there are plenty of polls to support this. (This 2005 ABC News poll showed that 43 percent of Americans approved of Congress but 65 percent approved of their own congressman.)
Further, a surefire way to build support at home is to loudly and repeatedly proclaim your independence from, well, everybody and everything -- including your own party, the president, the media, special interest groups, ideological groups, and whichever mentors have helped your political career. (If you're a married man, however, it's mandatory for you to joke that your wife makes all the important decisions.)
I just don't see how waving around charts about the generic approval ratings for Congress will help Obama win votes for legislation. It's a different story with congressmen and senators who face serious primary or general election opponents next year -- when Obama can promise to campaign for an incumbent or stay out of the race, depending on the district -- but there aren't likely to be more than a handful of such cases.