Republican grandees gushed over the youngish star of the GOP, even those – such as former House speaker Newt Gingrich – who had previously dismissed his tax plan as 'right-wing social engineering'.
Meanwhile many Democrats were also whooping it up over the decision, in the belief that the pick would be unpopular with the public at large due to the swingeing spending cuts Ryan proposes.
Bill Burton, a former White House staffer and founder of leading Obama Super Pac Priorities USA, tweeted: 'Romney picked one of the only people who could have had an impact in the race. But, not the way he wants'.
It was a view that many shared.
Over at the Washington Post, liberal-leaning columnist Ezra Klein suggested that the move could play into president Barack Obama's hands.
He wrote: 'Romney's original intention was to make the 2012 election a referendum on President Obama's management of the economy. Ryan makes it a choice between two competing plans for deficit reduction.
'This election increasingly resembles the Obama campaign's strategy rather than the Romney campaign's strategy'.
Meanwhile, Timothy Noah at the New Republic described the VP pick as a "fantastic stroke of luck" for Obama.
'Presidents presiding over the sort of economy we have right now don't usually get re-elected. But a president handed the opportunity to run against a GOP ticket that's unabashedly in favor of abolishing Medicare – something even the Tea Party opposes – would probably win in November', Noah wrote.
There was no immediate reaction from the White House. But Jim Messina, Obama's campaign manager, took little time before he went on the offensive.
'As a member of Congress, Ryan rubber-stamped the reckless Bush economic policies that exploded our deficit and crashed our economy. Now the Romney-Ryan ticket would take us back by repeating the same, catastrophic mistakes', he said
Many commentators have suggested that plumping for Ryan was a 'high risk, high reward' strategy.
Those on the political right, tended to focus on the reward part of that equation.
Former governor of Florida Jeb Bush, described it as a 'courageous choice'.
'Congressman Ryan's command of economic policy and the federal budget will prove invaluable as Governor Romney fights to reform government, accelerate job growth and rein in the out-of-control spending that has been a hallmark of President Obama's years in office', Bush said.
Media mogul Rupert Murdoch tweeted: 'Thank God! Now we might have a real election on the great issues of the day. Paul Ryan almost perfect choice'.
Meanwhile, Newt Gingrich has seemingly had a change of heart since dismissing Ryan's tax plan earlier on in the primary season.
'We're very, very happy', he told CNN, adding that the young Republican had grown into 'one of the great intellectual leaders' in America today.
As to that 'right-wing social engineering' comment, it appears that Ryan had 'listened carefully' to the former House speaker in recent months and had now learned the error of his ways.
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image: © Gage Skidmore