Three things are clear: 1) Job losses in this recession are already much worse than the Obama administration anticipated; 2) The stimulus designed to slow the pace of job losses has either proven too weak or too slow in its effectiveness; 3) The idea of passing a second stimulus, once a baby of the liberal blogosphere, has grown up to occupy the attention of major figures like George Stephanopoulos on ABC. Still, I would put my money on a second stimulus not happening, for the following three reasons:

First, the Obama administration would be going back to the Congress with some humbling data. The White House predicted that the stimulus spending would dampen unemployment, and they provided a clear graph to show just how crucial stimulus spending would be to save jobs. But the last few months have seen unemployment sky-rocket almost a full percentage point higher than the administration envisionsed without a stimulus at all. This graph below could act as a kind of negative political capital, discouraging conservative Democrats from throwing more money at the recesssion.
Second, it's not a given that the money from a second stimulus would be spent any quicker than the first. Take a look at this graph of stimulus spending, which is provided by the Obama administration at their site recovery.gov. It seems that every week, the administration makes "available" about $6 billion and spends about $3 billion.
As of late June, we had only paid out about one-third of the available funds, and about 15 percent of all spending allocated in the recovery bill. To be sure, Obama has promised that the pace of spending would increase this summer. But if we can't spend all of the stimulus even by November 2010, as the administration admits, how much faster would another couple hundred billion be spent? That's a question I expect the Obama administration will have to answer if they get their second stimulus.

Third, I expect that the politics of shifting attention away from one of the three big issues of the docket -- health care, climate change and bank regulation -- are dangerous. Conservative Democrats -- and a solid majority of Americans -- are getting nervous about deficits at a time when the Obama administration is pressing them to help pass a trillion-dollar health care reform bill and a potentially even more costly climate change bill to cap carbon emmissions. Say what you want about the long-term impact of climate change and health care reform, but they're going to cost an intimidating sum over the next few years. If Obama presses for a second stimulus, I expect he'll meet plenty of resistance from his own party. Politicians should be nervous about these job losses, but come 2010, they'll be most worried about losing their own.