Joe Biden's "rhetorical flourish" about Obama being "tested" appears to have gained a bit of traction.  I'm not sure it will do any lasting damage, but why risk it?  Biden could easily turn things around by pointing out two simple facts:

1).  When John McCain asserts that Obama would be tested by our enemies but that he would not, he's either being dangerously arrogant or cluelessly naive.  Any new administration will be tested for weakness, style, etc.  To assume that you've already been tested, as McCain is doing, is absurd.  There's no presidential aptitude test that you take once and then go on your merry way.  Biden needs to point this out.  John McCain will be tested, and he will most likely fail because he doesn't have the temperament of a leader.  He is erratic, indecisive, hot-headed, impulsive and unpredictable.  Precisely what we don't need in these dangerous times.

2). If something were to happen to McCain, Sarah Palin would most certainly be tested.  That is a prospect too frightening to consider.  She is hopelessly unprepared for the job, and Sarah Palin in the Oval Office would put our nation's security in grave danger.  We can not afford to take a chance on either one of them.

Obama has made his case.  He's passed the Commander-In-Chief threshold for the majority of Americans.  This is the perfect opportunity to drive the final nail in the McCain campaign's coffin.