In a “Today” show appearance Tuesday morning, Rep. Paul Ryan (R-Wis.) said he hadn’t seriously considered being tapped as Mitt Romney’s running-mate.

But the House budget chairman has already settled comfortably into a traditional VP role: attack dog.

Asked why President Obama was targeting the congressman’s budget as a “Trojan horse” and “social Darwinism,” Ryan dismissed the president’s critiques.

“You know, we’ve gotten kind of used to this sort of verbal tantrums from the president. To me it’s a little more petulance than presidential,” Ryan told NBC. “He’s trying to use this kind of rhetoric to distort away from his failed record.”

Visit for breaking news, world news, and news about the economy

Ryan used the same phrase (which echoes an editorial defending Ryan in the conservative National Review) on MSNBC’s “Morning Joe” a few minutes later,. He added that Obama’s much-touted Buffett Rule is “pixie dust.”

The crack is a reminder of Ryan’s speech on the night of the Wisconsin primary, a series of one-liners that helped spark newfound buzz about the lawmaker’s vice presidential prospects.

Of course, it’s still very early in the veepstakes, as Ryan himself said. Ryan and Obama have been exchanging barbs since last week.

But the Republican’s latest salvos are unusually sharp and a sign that the congressman is happy to be elevated from policy wonk to White House target.