As we mourn the dead and wounded, focus inevitably turns to the political war fought in the blogosphere and on Twitter before the facts were known.

There were plenty of hateful tweets on all sides and in all directions. There also were attempts by people like Nick Kristoff of the NY Times, Charles Pierce of Esquire, and Chris Matthews of MSNBC, to name a few, to take political advantage.

But one tweet stood out for its sheer pathology.

Richard Silverstein is a well-known left-wing hyper-critic of Israel and apologist for anti-Israel extremism, who runs the Tikun Olam website.

Silverstein tweeted that although he didn’t know who was behind the attacks in Boston, if they were Islamists, the United States would be to blame:

Twitter - @TikunOlam - Boston Marathon1

In case there were any doubt, when called out on it Silverstein doubled down, invoking drone killings:

Twitter - @TikunOlam - Boston Marathon2

The tweet is pathological in so many respects and on so many levels, precisely because we don’t know who did it or what motivated them.

Yet excuses already are being made and justifications being lined up for Islamists, if they were indeed behind it.