Rep. Paul Ryan said on CBS' "Face the Nation" Sunday that he didn't voice his opposition to the government shutdown in 2013 because he wanted to ensure there was "party unity."
"I don't think it was constructive for conservatives to be carping at each other. At the same time, the purpose of that passage is to try and unify our party. I don't think we can succeed if all we do is criticize and define what we are against," he said.
Ryan wrote in his new book that came out last week that he believed the Republican attempt to defund Obamacare by shutting down the government was "a suicide mission" but that too many members of his own party were unwilling to abandon the idea for fear that they would be punished by outside groups aligned with the tea party.
He told CBS News' Bob Schieffer that he didn't believe the strategy was "really legitimate" because a government shutdown cannot stop an entitlement program, not to mention there was no support for the strategy in the Senate.
But the point of his book, he said, "to help design a unified conservative Republican movement that is principled, inclusive and aspirational so that we can win a majority of Americans' votes to save this country from what I believe is going down the wrong track."
He wrote in the book that as the 2012 vice presidential nominee, he pushed former Massachusetts Gov. Mitt Romney's campaign to lay out an alternative to President Obama's leadership, but he felt they were too focused on attacking Obama's record. Still, Ryan said that there were "a whole multitude of reasons why we didn't win."
But he has not given up his own faith in Romney. Ryan said he wished he would run for a third time, even though Romney has said he won't.
"I think he'd make a phenomenal president. He has the intellect, the honor, the character and the temperament to be a fantastic president. You know, I wish everybody could see the guy that I know," he said.
As for his own future, Ryan said that he and his family would weigh a possible presidential bid very seriously and decide in 2015.
Asked if he would support Sen. Ted Cruz, R-Texas, who led the shutdown strategy, or Sen. Rand Paul, R-Ky., who advocates for a less aggressive American presence around the world, Ryan said he would back either colleague.
"I would support either of those people if they become our Republican nominee. I think there are going to be a lot of other people in this race," he said. "I have differences with different people in the party but that's okay. I want to have a big Republican party with a big tent that gives the country a better future that can win the majority of votes in this country. We need to win the Electoral College. We need to win national elections so we can get this country on the right track. And whoever our nominee is going to be is going to need everybody's help."