Perhaps the only surprise at all is that, in contrast to a year ago, it took Biden quite this long to become the president’s point man on the latest round of fiscal talks. The exact reason for the delay is not clear. Perhaps it is that, only a week and a half ago, Obama had called on his vice president to lead a commission to expedite recommendations on a truly serious national issue, gun violence (as opposed to the present trumped-up issue, fiscal reform, which requires only the smidgeon of political courage necessary to depart from ideological rigidities). Maybe Obama wanted to keep his veep’s powder dry for that.

Or maybe it is just that, in the awkward pattern of political dance partnerships that have emerged over the last couple of years, whenever Barack Obama and Speaker John Boehner fail to execute – as they did after the “Plan B” debacle — it’s Biden and his old Senate colleague, Mitch McConnell, who step into the spotlight. The Biden-McConnell duo didn’t cut it during last year’s cliffhanger over the debt limit, of course. But in a sign of just how important a figure the vice president has become in Washington, Biden’s absence until now has been one reason that Republicans doubted Obama’s seriousness about cutting a deal, my colleague Chris Frates reported last week.

As the inevitable brinksmanship plays out, it’s useful to step back and look at just how central a role Biden has played throughout Obama’s presidency.