It started happening long before Bush.
You might want to start with Jimmy Carter and the Community Reinvestment Act (CRA) that he signed into law which eventually lead to the relaxing of credit standards.
In his early activist days, Barack Obama the community organizer sued banks to ease lending practices.
In 1994, Barack Obama was one of the plaintiffs in a class action lawsuit, alleging that Citibank had engaged in practices that discriminated against minorities. The lawsuit forced the bank to ease its lending practices.
In 1995 Bill Clinton rewrote the CRA, loosening housing rules by forcing banks to lend in low-income neighborhoods.
By the time George Bush was President the CRA regulations were already in place and most of these bad mortgages had already been made.
The Bush Admin and Senator McCain warned the Democrats repeatedly about Fanny Mae and Freddy Mac as early as 2002
But Democrats Schumer, Frank & Dodd would do nothing and blocked any attempt to tighten credit regulations.
The 2003 American Dream Act, allowed loans for 1st time home buyers, with low incomes, but credit worthy, and helped with their closing costs and down payment. It can take a long time to get enough money together for a down payment and closing costs, but these people were suppose to be otherwise credit worthy, which is different from what the relaxed credit standards that the CRA caused. They had folks with no documented income getting home loans. Now did some of these 2003 American Dream Act folks get in on the 125% refinance loans, probably so. But Bush didn't create that.
JMHO, Lindy
"Buy low, Sell high, stay with your system. If your system breaks fix it."