According to The Washington Post’s Dana Milbank, Barack Obama’s biggest challenger this election season is his own hubris. Milbank details the way Obama has been swaggering around Washington as if he’s already the President.

Barack Obama has long been his party’s presumptive nominee. Now he’s becoming its presumptuous nominee.

Fresh from his presidential-style world tour, during which foreign leaders and American generals lined up to show him affection, Obama settled down to some presidential-style business in Washington yesterday. He ordered up a teleconference with the (current president’s) Treasury secretary, granted an audience to the Pakistani prime minister and had his staff arrange for the chairman of the Federal Reserve to give him a briefing. Then, he went up to Capitol Hill to be adored by House Democrats in a presidential-style pep rally.

Along the way, he traveled in a bubble more insulating than the actual president’s. Traffic was shut down for him as he zoomed about town in a long, presidential-style motorcade, while the public and most of the press were kept in the dark about his activities, which included a fundraiser at the Mayflower where donors paid $10,000 or more to have photos taken with him. His schedule for the day, announced Monday night, would have made Dick Cheney envious…

In the latest issue of the New Republic, Gabriel Sherman found reporters complaining that Obama’s campaign was “acting like the Prom Queen” and being more secretive than Bush. The magazine quoted the New York Times’ Adam Nagourney’s reaction to the Obama campaign’s memo attacking one of his stories: “I’ve never had an experience like this, with this campaign or others.” Then came Obama’s overseas trip and the campaign’s selection of which news organizations could come aboard. Among those excluded: the New Yorker magazine, which had just published a satirical cover about Obama that offended the campaign.

Even Bush hasn’t tried that. But then again, Obama has been outdoing the president in ruffles and flourishes lately. As Bush held quiet signing ceremonies in the White House yesterday morning, Obama was involved in a more visible display of executive authority a block away, when he met with Pakistani Prime Minister Yousaf Raza Gillani at the Willard. A full block of F Street was shut down for the prime minister and the would-be president, and some 40 security and motorcade vehicles filled the street.

Later, Obama’s aides issued an official-sounding statement, borrowing the language of White House communiques: “I had a productive and wide-ranging discussion. . . . I look forward to working with the democratically elected government of Pakistan.”

It had been a long day of acting presidential, but Obama wasn’t done. After a few hours huddling with advisers over his vice presidential choice, Obama made his way to the pep rally on the Hill. Moments after he entered the meeting with lawmakers, there was an extended cheer, followed by another, and another.

“I think this can be an incredible election,” Obama said later. “I look forward to collaborating with everybody here to win the election.”

Win the election? Didn’t he do that already?

Keep in mind that Dana Milbank is no moderate. He’s one of Keith Olbermann’s left-wing shills, so it’s pretty interesting that he would write a piece like this.