it was a "political tool" long before it actually happened

it was a campaign promise in the 2008 season - that's where the quote comes from

OBAMA: What I've said is we're going to encourage democracy in Pakistan, expand our nonmilitary aid to Pakistan so that they have more of a stake in working with us, but insisting that they go after these militants. And if we have Osama bin Laden in our sights and the Pakistani government is unable or unwilling to take them out, then I think that we have to act and we will take them out. We will kill bin Laden; we will crush Al Qaida. That has to be our biggest national security priority.

(this was from the debate in which McCain memorably said "I'll get Osama bin Laden, my friends. I'll get him. I know how to get him. I'll get him no matter what and I know how to do it.")

so we're talking about a specific course of action which a presidential candidate openly expressed his intentions to complete

this course of action was taken and successfully accomplished - and widely received as an achievement for the obama administration

this is not just randomly taking credit, though!

during this same campaign, the proposed pakistan incursion was criticized by the gop, and romney took part in this (as we have seen)

now we see the transition of this event into what is now called a "unifying moment", but in fact the proposal of the very same process was itself criticized.

it was not a unified plan to conduct a military operation into pakistan for the purpose of killing obl! obama was ridiculed for this!

so yes, obama will take credit for taking an action promised in the last campaign (which was opposed outright). it is strange to call this petty and pathetic. it is a rare issue on which obama is particularly strong and decisive.

also, kerry was indeed criticized for voting against intelligence/military funding in the lead-up to 9/11 - it was a pretty notable part of the campaign to prove he was wrong for america on national defense (ie. these liberal cowards voted in a manner which made america less safe and allowed 9/11 to happen, and aren't supporting our troops in iraq)