MSNBC host David Gregory accused Ryan of "ideological amnesia" for papering over his own role in helping rack up large deficits.
"He is a man -- as I know that you've all referred to this -- who did vote for the auto bailout, he did vote for TARP, he did vote as well for both wars that were not funded, and he voted for Part D of Medicare, and he's spent his entire life in government," Gregory said.
Washington Post opinions editor James Downie called the speech "breathtakingly dishonest" in a headline at his paper's PostPartisan blog, declaring in his opening paragraph that it was "filled with falsehoods from start to finish."
Downie concluded with a plea to reporters: "With tonight's speech, Mitt Romney and Paul Ryan have doubled down on their twin bets of 2012 -- that journalists will sit back and name winners and losers without regard to who is telling the truth, and that voters are too ignorant to care about the truth. Do not let them be right."
The Boston Globe's editorial page editor noted in a headline that Ryan's attacks on the president "may hurt his own credibility."
After noting that conservatives were elated by his speech, Peter Canellos added: "But Ryan's bill of particulars against Obama strained credibility enough to damage his own, not-quite-earned reputation as a straight shooter."
The media backlash focused most intently on Ryan's assertions about the federal budget and Medicare, in which he inaccurately characterized Obama's policies and neglected to mention his own role in advancing some of the same goals. The single largest point of hypocrisy: Ryan attacked Obama for cutting Medicare by over $700 billion -- savings, wrung largely from reducing overpayments to private insurers and hospitals, that Ryan has included in his budgets and supported until he became Romney's running mate. Many also took on Ryan for bashing Obama for the closing of a plant in Wisconsin that shuttered under President Bush.
The pushback could damage Ryan's reputation for sincerity among members of the media establishment, which has been key to his identity as a reformer. It might also escalate tensions with reporters who are already pressing the Romney campaign for its inaccurate attacks on Obama's welfare policy, and his remarks about entrepreneurship, that the GOP has taken out of context.
On the CNN panel with Blitzer, host Erin Burnett also gently chided Ryan. "We were jotting down points," she said. "There will be issues with some of the facts."