It's manufactured "tense."
The neat thing about the show (I watch it religiously on Bravo) when Sorkin was writing the dialogue was quick and witty and the drama was simply folded in. You hardly noticed your emotions were being manipulated

It wasn't in your face tension for tensions' sake. That's probably a piss-poor way to describe it, but what can you do?
Lowe left leaving a big ass gaping hole that they tried to fill. Just when the replacement character was starting to come round they relegate him to a background player.
This last season is filled with stupid camera angles, uncomfortable silence and, like Kadath mentioned, played out gimmicks.
The guy left to fill Sorkin's shoes producer wise, John Wells does a couple of shows for NBC; Third Watch and ER. That's sort of what the West Wing has turned into. This mush of trite drama inducing crap that plagues television. Instead of relying on good writing to bring folks around (a la Aaron Sorkin) they've resorted to forced melodrama (ER had a helicoptor crash and a tank "problem;" Third Watch consistently kills off cast members to boost ratings)
I know I'm ranting, but this season is such a let down from the previous. There are good parts in the latest season to be sure, but nothing compared to the stuff of the last couple of years.