Kerry is a high ranking Senator, in all honesty, and if he was actually attending Congress, I would say that he didn't need the briefings. He is not, however, so he should at least take the offered intelligence.
Clinton was NOT in the Senate, and did the right thing by taking them.
There are some things that the candidates should know, regardless of the acrimony, both to keep from looking foolish by not knowing something, and also to show that he is involved.