President Barack Obama keeps trying to give former Massachusetts Gov. Mitt Romney credit for the Affordable Care Act, which tells you how unpopular Obamacare is.

Romney, Obama told the public radio show “Marketplace,” “is now pretending like he came up with something different” from Obamacare, which celebrated its second anniversary last week.

Like Obama, Romney’s GOP primary rivals Rick Santorum and Newt Gingrich also are talking as if Romneycare spawned Obamacare, as both plans rely on an individual mandate.

But the philosophies behind the federal plan and the Massachusetts plan are radically different. Romney set out to offer a plan that would address the state’s 460,000 uninsured residents, without putting undue burdens on state employers. Obamacare, conversely, is mandate heaven. Its expanding array of benefits effectively has created a new tax on employers. Already, for example, health plans must offer coverage for employees’ adult children up to age 26. Obamacare provisions to end copayments for “preventive care,” including birth control, may seem like savings for workers, but someone has to pay for all that free stuff.

“Free preventive services is a misnomer,” the Boston-based Pioneer Institute’s director of health care policy, Josh Archambault, told me. “It will often be passed on through higher premiums.”

This goes to the fundamental problem with Obamacare. As a candidate, Obama promised to sign a universal health care package that would “cut the cost of a typical family’s premium by up to $2,500 a year.” But in larding the health care menu, Obamacare gives consumers little to no reason to contain costs.

The Kaiser Family Foundation found that employer-sponsored health care costs rose 9 percent last year, and part of the credit went to the Affordable Care Act’s mandates, which will not take full effect until 2014.

Romneycare also included minimum coverage requirements to protect consumers. But the Romney model promoted flexibility, individual choice and responsibility. Instead of giving away benefits, Romney concentrated on providing medical care in a cost-sharing framework to encourage families to make smart choices, healthwise and moneywise.

As for the individual mandate, Romney called it “the ultimate conservative idea,” Boston Globe scribes Michael Kranish and Scott Helman reported in their book, “The Real Romney.” Romney believed that the mandate told people, “Don’t look to government to take care of them if they can afford to take care of themselves.”

In drafting the Affordable Care Act as it is, Obama has told people they cannot afford to take care of themselves. Period.

Archambault uses an apt analogy to compare Romneycare with Obamacare. “Massachusetts is a car. It’s smaller. It’s easy to fix. Problems can still arise, but it’s much easier to steer.”

Obamacare, he continued, “is like a train. It still has wheels and an engine like the car, but it’s much bigger. It runs through all areas of health care, and it’s inflexible. Once the track is laid, it’s very difficult to change the direction.”

Debra J. Saunders is a San Francisco Chronicle columnist. Her email address is dsaunders@sfchronicle.com.