Nate Silver thinks that the House may be a bigger hurdle than the Senate:
According to the WSJ, Dashale has said: "I think the risk of failure goes up consequentially if we don't get it done by the August break." DiA parses.1. Yes, the Blue Dogs really do have some leverage here. It's at least conceivable that the House would be unable to approve health care while the Senate would be.
2. And/but -- if the bill passes by a narrow margin in the House (even by just a few votes) that will not necessarily doom its chances of overcoming a filibuster in the Senate. Nor does the fact that the bill is having some trouble in the House necessarily mean all that much in terms of its prospects in the Senate. The Senate Democrats operate within a much more narrow band ideologically -- there are proportionately fewer true Blue Dogs, and also proportionately fewer uberliberals. If the White House could get assurances that a few key senators like Nelson, Landireu and Snowe won't filibuster health care -- they don't actually have to vote for the bill -- the Senate landscape actually starts to look reasonably favorable to the bill, possibly more favorable than the House's.