When Paul Ryan introduced his radical budget plan this year—which would turn Medicare into a voucher system, privatize Social Security and massively redistribute income upward by drastically cutting taxes for the wealthiest one percent while severely slashing programs for low-income Americans—Mitt Romney heartily applauded.

“I applaud Rep. Paul Ryan for recognizing the looming financial crisis that faces our nation and for the creative and bold thinking that he brings to the debate,” Romney said in April 2011. “He is setting the right tone for finally getting spending and entitlements under control. Anyone who has read my book knows that we are on the same page.”

Now Romney has gone a step further, actively incorporating Ryan’s ideas into his own plan to reduce the social safety net, which he outlined at the Koch Brothers–funded Americans for Prosperity convention on Friday. Romney would raise the eligibility age for Social Security and Medicare, cut $100 billion from Medicaid and allow seniors to pay for health coverage through vouchers for private insurance (a shrewd way to undermine the immensely popular government-run Medicare program).

After the speech, Washington Post blogger Jennifer Rubin wrote that Romney “has found his inner Paul Ryan.” Ryan, in turn, told Rubin that Romney’s plan was “a great development…. This tracks perfectly with the House budget.” The Wisconsin congressman gushed to National Review: “It shows we’re all singing from the same hymnal.”

Given the unpopularity of the Ryan budget, Romney may come to regret this endorsement. It may help him win the votes of Tea Party conservatives in the GOP primary, but it will almost certainly become a liability in a general election campaign against President Obama.