Politics: The White House isn't likely to enact a sweeping program that might benefit riskier borrowers. And the Federal Housing Finance Agency, which regulates Fannie Mae and Freddie Mac, hasn't embraced many such programs. Instead, the White House may expand an existing refinance program that more carefully targets suitable homeowners. The program has helped some 838,000 people refinance, but has been roundly criticized as lacking broad impact — in part because as many as 4 million homeowners appear to have met eligibility requirements but received no assistance.