President Obama on Tuesday began another effort to boost the fragile housing market, but with mortgage rates rising, some experts wonder whether the White House has missed its window for making the American Dream more affordable.

In Phoenix, one of the areas hardest hit by the housing crash, Obama vowed not just to help homeowners who still owe more than their house is worth but also lay the foundation for reforms that would keep the bubble from bursting again.

Obama has yet to deliver the type of comprehensive relief to the housing sector he promised early in his term, a reality he delicately acknowledged in his latest economic speech.

"The truth is it's been a long, slow process that's taken longer than any of us would like," he conceded Tuesday.

Still, Obama pointed to a "healing" housing market, trumpeting home prices rising at the fastest pace in seven years and foreclosures down by nearly two-thirds during that period.

Some analysts were far less glowing in their assessment of Obama's housing efforts.

"I think housing is one of the areas they did particularly poor in - they had a chance to help people and they muffed it, " said Dean Baker, co-director of the Center for Economic and Policy Research. "I think they were slow with painfully, badly designed proposals."

Americans never signed up to refinance their homes at the clip the administration expected. And with the average 30-year fixed-rate mortgage jumping to 4.59 percent -- from 3.52 percent at the beginning of May -- the incentive to do so is dropping. And such an option no longer exists for those who were forced to give up their homes during the height of the recession.

As for the housing market's long-term security, Obama pressed for the winding down of taxpayer-backed mortgage titans Fannie Mae and Freddie Mac. But at the same time, he called for a new system to ensure the viability of 30-year mortgages -- a blueprint that would at least maintain a federal safety net in case of another crash.

It's an approach that supporters trumpeted as a way to make housing more obtainable, put more emphasis on private capital and reduce the influence of Fannie and Freddie.

"Our ... approach protects taxpayers while maintaining access to affordable mortgage credit," said Sen. Mark Warner, D-Va., co-sponsor of a bill being embraced by the White House. "Our proposal also will end the current Fannie and Freddie model of private gains and public losses. I look forward to getting to work on this issue with my colleagues in September."

But some economic experts said Obama was repeating the mistakes of the past.

"Their proposal is a plan to subsidize mortgage-backed securities," Baker said. "I can't say I'm happy about where they seem to be going with this. The goal is wrong-headed -- it's great for people to be homeowners -- and I don't see the safeguards in place, meaning we're just back to where we were."

Just ahead of Obama's speech, the Justice Department announced it had filed a civil lawsuit against Bank of America, accusing the company of defrauding investors on $850 million worth of mortgage-backed securities.

Obama is trying to balance boosting home ownership rates, which are at an 18-year low of 65 percent, and putting in the oversight needed to prevent aspiring home owners from going beyond their means.

The president said Tuesday that he is well aware of the traps that caused the last housing crash.

"No more leaving taxpayers on the hook for irresponsibility or bad decisions," he said of Fannie and Freddie. "The era of expecting a bailout after your pursuit of profit puts the whole country at risk is over."