It is Romney-Perry now, with plenty of differences

As Rick Perry and Mitt Romney jockey over their ability to defeat President Barack Obama, there are deepening fault lines between the two on Social Security, immigration, jobs and more that could shape the contest.Their stylistic differences are as stark as their disagreements on substance. Romney, the former Massachusetts governor, also is a former venture capitalist who is at his best when hes talking about how to help businesses help the economy grow. Perry, the Texas governor, is a fiery, red-meat conservative who has already shown he loves to go on the attack — and isnt afraid to go after his chief GOP rival.Those contrasts have driven Romneys campaign to fundamentally change a strategy that was previously aimed squarely at Obama. Until Perry jumped into the race and almost immediately displaced Romney as the front-runner, the former Massachusetts governor focused his public appearances and messaging on the president.Now, instead of running a general election campaign in primary season, Romney will spend the early months trying to convince Republicans that Perry cant beat Obama in November.It will start with Social Security, an issue Romneys campaign has decided is Perrys biggest liability. Aides privately say they plan to make it a singular focus in the coming weeks.You say that by any measure, Social Security is a failure. You cant say that to tens of millions of Americans who live on Social Security and those who have lived on it, Romney said in Wednesday nights debate, after he and Perry had already traded jabs over their jobs records earlier in the debate.The Romney campaign has followed that with a steady stream of press releases, background material and on-the-record quotes assailing Perry as a career politician who is unelectable.If (Perry) were to win the nomination, the most interesting thing that it would prove is that God is a Democrat, said Stuart Stevens, a top Romney strategist.Romney has also started to take on Perrys immigration record. Advisers say that could be the next front in the fight, largely because it could hurt Perry with the conservative base he relies on. As governor of a border state with problems related to illegal immigration, Perry has said a physical border fence isnt necessary. Texas universities also allow the children of illegal immigrants to pay in-state tuition rates.