They bought a lot of loans they shouldn't have. But this wasn't some Democratic scheme to get Black people homes they shouldn't have. Rather, the bosses at Fannie Mae and Freddie Mac structured their pay so the more loans they moved the more they got paid. And then they moved every loan they could get their hands on, no matter the quality. They even cooked the books to cover up the real risks and expenses until they got caught.
People who bought homes through the government programs actually have a lower default rate then the national average.
Jay