Mark down May 20 on your calendar

After the Pennsylvania primary, I argued that superdelegates should endorse Obama or join the Pelosi Club by May 20, the day on which Obama secures a pledged delegate majority. If enough of them did so, Obama would be become the presumptive nominee as the voters put him over the top of the 2,025 threshold instead of insiders.

It would be far preferable to any of the June scenarios, almost all of which would allow the media (perhaps justifiably) to create a potentially damaging narrative about Obama's victory.

Now it's starting to look like it might actually happen if Hillary does not withdraw sooner. Apparently, the Obama campaign is thinking along the same lines. I also heard Tim Russert float the idea last night and kos suggested it as well.

Update: Kos posts the Obama campaign memo to superdelegates, which also mentions the May 20 date. And in this post kos flat-out states he believes Obama will have the nomination wrapped up on May 20, with Oregon putting Obama over the top.