The Republicans tried to pass two separate bills in 2005 - one in the House, and one in the Senate. In both cases, Democrats were the obstructionists. In the House, Barney Frank’s Finance committee opposed it, and in the Senate, the House Banking Committee couldn’t get it through. It was controlled by Republicans, but they still needed 60% of the vote to get it out of the committee, and it failed with the vote along straight party lines - all Democrats against, all Republicans for. This also sent a signal to Republicans that the Democrats would oppose it if came to a floor vote, and maybe even stage a filibuster. So instead the bill remained in committee. Then an amendment was attached to it to stall it, and eventually time ran out on that session of the Congress and the bill died. This was S.190.
President Bush issued repeated warnings against the excesses of Fannie and Freddie, almost from the day he was in the White House.
When the Democrats took power in the House and Senate, all legislative activity with regards to Fannie and Freddie came to a standstill.
To understand why Democrats behaved this way, you have to know that Fannie and Freddie were a social engineering project - their job was to underwrite risk so that low-income people could afford to buy homes. It was a form of social welfare for the poor and minorities, and therefore Democrats supported them, and saw attempts to regulate them as mean old Republicans trying to shut down social programs.