that's pretty much been the Clinton M.O. this election cycle.  They'll try to get something to stick before the vote -- that much we can be sure of.  Anything less would be out of character for the Clintons.

I am a little worried about it, although I think if they had any more dirt on Obama they would have brought it out before Super Tuesday or before Ohio and Texas. They never planned beyond Super Tuesday, so I would think they'd have used anything they had to knock him out then. That does not preclude them exploiting any gaffes or whatever that he has made since then or could make in the next two weeks, but I doubt they have a lot more dirt on his past than they have already brought out.

She could surprise us by dropping out. The woman is broke and her #s don't look good. Most people already dislike her because of her negative campaign. I'm sure she wouldn't want to ruin her chances in the fall IF she gets the nomination.

The Clinton campaign never expected this thing to last this long and they fired off most of their reserve oppo research stuff in the lead-up to Texas and Ohio.

Most likely whatever they use pre Pennsylvania will be something they've picked up recently or something way nasty that they thought was too badass to use, even in the dark days before Texas. If so, whatever they use in the week pre 22nd April might well fail, either because of incomplete vetting (snipers anyone?) or becuase it's so over the top nasty that it backfires.

Your operative is dead right about timing though. And that choice of timing is a hint that whatever it is is pretty brutal.