In his mind's eye, President Obama likely envisioned the 48 hours after Nov. 6 as days of celebration -- having scored a convincing victory and a second four-year term.

President Obama and former CIA Director David Petraeus. Photo by J. Scott Applewhite
Credit: AP

Instead, Obama was forced to confront the resignation of CIA Director David Petraeus after he acknowledged an extramarital affair and the resultant uproar in Congress about why they didn't know more earlier. (In Obama's defense, he was only informed about the Petraeus situation on Thursday morning.)

The Petraeus story combines two of Washington's favorite subjects -- national security intrigue and a tawdry sex scandal involving a very high-profile public figure -- and, if the coverage over the weekend is any indicator, seems unlikely to go away any time soon.

Petraeus's resignation also comes on the eve of closed door hearing of the Senate Intelligence Committee aimed at trying to find exactly what happened on Sept. 11, 2012 when four Americans -- including Ambassador J. Christopher Stevens -- were killed in attacks in Benghazi, Libya. Petraeus has said he doesn't plan to testify at the hearing despite some within Congress insisting he should.

The Petraeus scandal -- and its fallout -- highlights the perils of the modern presidency and, specifically, the inability to stay on a single message for very long.

President Obama clearly wanted to spend the week (at least) after the election capitalizing on the momentum/mandate gained in last Tuesday's election to pressure congressional Republicans on the looming fiscal cliff negotiations.

In his first public comments following his victory Tuesday, Obama repeatedly asserted that the election had proven that "the majority of Americans approve of my approach" on the fiscal cliff. And, you can bet that Obama's scheduled press conference on Wednesday was conceptualized by his senior aides as another opportunity to drive that same message home.

And while Obama will, of course, get plenty of questions on fiscal cliff, he's also likely to now get his fair share of Petraeus-related questions too -- none of which he has good or easy answers for.

That split attention span will complicate -- though not likely obscure -- what Obama would like to be the central message coming out of the White House: I won and now it's time for Republicans to deal on debt and spending.

Driving a single message has never been an easy task as the president but it's become that much harder in the age of Twitter -- not to mention the growth of political cable television as a driver of intraday conversation. (It's worth remembering that Obama is the first president to be forced to deal with the challenges of Twitter and social media more generally; Twitter was invented in 2006 but really came of age, politically speaking, in the 2008 campaign and beyond.)

We now live in a double split-screen world: 1) All news programming features not only its main offering but a bar, typically filled with tweets, scrolling across the bottom of the screen and 2) Lots of the most active news junkies consume televised events with their computers open and tuned to Twitter.

That reality makes dominating a news cycle -- much less many news cycles -- extremely difficult for any politician, even one who commands as much attention with every utterance as President Obama. And it's why the Petraeus news couldn't have come at a worse time for President Obama.