Well, let me make a stab at it:
A very lame duck president (whose only role seems to currently be to help his party mate get elected), an opponent who doesn't seem to be able to keep his facts straight on subjects that are important to world politics, and who focuses on a surge that has run its course.
But Frank Rich makes a very good case in his NY Times column including:
The growing Obama clout derives not from national polls, where his lead is modest. Nor is it a gift from the press, which still gives free passes to its old bus mate John McCain. It was laughable to watch journalists stamp their feet last week to try to push Mr. Obama into saying he was “wrong” about the surge. More than five years and 4,100 American fatalities later, they’re still not demanding that Mr. McCain admit he was wrong when he assured us that our adventure in Iraq would be fast, produce little American “bloodletting” and “be paid for by the Iraqis.”
...
Mr. McCain could also have stepped into the leadership gap left by Mr. Bush’s de facto abdication. His inability to even make a stab at doing so is troubling. While drama-queen commentators on television last week were busy building up false suspense about the Obama trip — will he make a world-class gaffe? will he have too large an audience in Germany? — few focused on the alarms that Mr. McCain’s behavior at home raise about his fitness to be president.
Once again the candidate was making factual errors about the only subject he cares about, imagining an Iraq-Pakistan border and garbling the chronology of the Anbar Awakening. Once again he displayed a tantrum-prone temperament ill-suited to a high-pressure 21st-century presidency. His grim-faced crusade to brand his opponent as a traitor who wants to “lose a war” isn’t even a competent impersonation of Joe McCarthy. Mr. McCain comes off instead like the ineffectual Mr. Wilson, the retired neighbor perpetually busting a gasket at the antics of pesky little Dennis the Menace.
...
Mr. McCain may be most comfortable at town-hall meetings before largely friendly crowds, but his performance under pressure at this year’s G.O.P. primary debates was erratic. His sound-bite-deep knowledge of the country’s No. 1 issue, the economy, is a Gerald Ford train wreck waiting to happen in any matchup with Mr. Obama that requires focused, time-limited answers rather than rambling.
Read rest at source.