I was certainly disappointed that Senator Obama did not forcefully oppose the FISA surveillance bill that passed the House yesterday. His lack of action here helps keep a bad bill alive, one which, should it become law, would set the awful precedent of condoning illegal behavior simply because the President asked companies to violate the law. Certainly there is risk that the new surveillance powers, due to the lack of any meaningful judicial oversight in using them, will be abused by the present, and future, administrations. This is a case of codifying that Presidential request is a valid excuse for breaking the law.

Senator Obama has shown outstanding political instincts, however, and it is quite likely that his judgment of the politics here is far better than mine.
1. Vocally denouncing the compromise, which has significant Democratic and virtually unanimous Republican support (only one Republican, Timothy Johnson of Illinois, voted no), would work against his attempts to portray himself as a practical politician who can work across party lines.
2. As Congressman Rush Holt noted, the bill sunsets in four years. Obama may rationalize his tacit support by his belief that he will win in November and will not abuse the power this bill would grant, mostly to him. And if he, as president, doesn't try to renew or extend it, the law will expire quietly, lessening the negative consequences of passage.
3. He has stated (along with Harry Reid) that he will try to get the retroactive immunity pulled from the bill. It's still an open question how hard he would try, or how effective such attempts would be, but the bill has not become law yet, and it may yet be amended further.
4. There's little political gain from opposing it strongly, but larger risk. Those who most strongly oppose FISA are overwhelmingly likely to support Obama for many other reasons. McCain gives unqualified support to the bill, so people voting on this issue have nowhere to turn. Now that the primary is over, Obama is understandably shifting more to the center to try to win independents and moderate Republicans, some of whom might believe this bill is "vital" in our war on terror.

If Obama opposed the bill, it would certainly push the issue of anti-terrorism tactics more to the foreground, and there's also a chance that having a more open, overt debate about that could wind up helping Obama. Undoubtedly it would be a big risk, and with his current strong standing in the polls, it's reasonable to think the risk isn't worth the potential gain. If he were trailing, and seemed likely to lose in November, a risky strategy would be more appealing.

Obama's handling of this reminds me of his handling of the Florida/Michigan revote proposals: had he actively and strongly supoprted revotes, they likely would have happened, and he may well have gained  politically from the new elections. But they also risked a large, public defeat that might have sunk his candidacy. When you're leading, don't risk the big mistake.

Retroactive immunity itself isn't what I (and, by projection, I believe without evidence most immunity opponents) care most about. What has me more upset is the disregard for the law shown by the Bush administration: its manipulating intelligence to whip up support for war; its twisted justifications of torture; and its arrogance in asserting it is beyond oversight of any other branch of government. The telecommunications companies who collaborated with the government here were "only following orders", which at least somewhat does mitigate their culpability. If allowing retroactive immunity is the price one has to pay for a more direct, public repudiation of the Bush administration's conduct, I'd take that trade. Winning only on retroactive immunity itself would be like convicting Al Capone for tax evasion: it's better than nothing, but it's not really the point.

So yes, I'm disappointed that Obama didn't strongly oppose this bill. But I can understand why, and his judgment is probably tactically correct here.