Your not alone in believing this. Democrats were in the forefront of preventing banks from redlining. They did not want loans denied on the basis of zip code. No one in Congress from either party, however, ever advocated for "no-income verification loans". Some on the left did try to push various programs to provide low income housing. These programs, without exception so far as I am aware, all resulted in low risk, Federally backstopped investment opportunities -- Title 8 would be one example. They were not intended to help the poor financially; they were intended to help get them off the street and into more stable surroundings. To get these programs through Congress a bone had to be thrown to the opposition. That bone was in the form of Federally backstopped, low risk investment opportunities. But these programs are not the cause of "liar loans."
Once misunderstanding takes hold, it is almost impossible to kill it. It lives on and plagues us for years. Wall Street was indirectly responsible for the liar loans, and the Fed was directly responsible. This had nothing to do with fair housing legislation, though some unscrupulous or ill-informed bankers may have suggested such. Virtually all mortgage money passes through banks at some point. The's Fed board of Governors is the ultimate authority when it comes to underwriting practice. Securitized mortgages became so popular, thanks to promotion by Investment Banks, that ultimately, once all the borrowers that could qualify under standard underwriting procedure practice were exhausted, the demand for Securitized mortgages continued. The investment banks looked the other way and held their noses as loan originators like Countrywide found ways to lend regardless of the borrowers ability to repay. Whole new categories of loans, such as interest only, were invented that could keep the raw material feeding the voracious loan securitizers fed. Greenspan, about two years prior to the crisis, began to receive, more less continuous, warnings of lax underwriting. He could have nips the entire fiasco in the bud, but that would have meant the demand for securitized mortgages could not be met! At the time, he was a firm believer that markets far from equilibrium will correct themselves more less harmlessly, just as they do in textbooks. He opted to do nothing. He was a Chief Regulator who did not believe in regulation!!!
I have been reading Greenspan's autobiography, "The Age of Turbulence." He admits now that he was remiss in not acting to shut down the liar loans. He has said publicly that he thought bankers would not act against their own best interests. Now, when it is too late, he has seen the light, and I don't imagine he still has such a firm believer that markets left alone will eventually self-correct excesses harmlessly. What Soros has taught us is that markets out of balance are more likely to go even further out of balance then they are to self correct harmlessly. He explains the reason for this market behavior using his "reflexivity theory."
The bottom line is that the push by the democrats for fair lending legislation to stop banks from red lining and for various public housing programs had nothing to do with the collapse of underwriting standards leading up to the financial crisis. The latter was driven by the investment bank's insatiable appetite for mortgages to repackage and made possible by Greenspan's insouciance in the face of dire warnings. There was so much money to be made, even those who knew the truth, who knew the quality of loans being bundled into triple A rated packages had deteriorated badly, kept their mouths shut. Their livelihoods and bonuses depended on remaining quiet. No banker, nor politician, ever publicly advocated for lax underwriting standards, nor did they push legislation that would have required the collapse of standards. But Bankers did make mortgage money available to originators who made their money from loan origination fees and were going to sell the loan the next day. They consciously violated underwriting standards because they could, they had no skin in the game. Meanwhile, everyone looked the other way. This fiasco had nothing whatsoever to do with fair lending/housing legislation, despite what some bankers have tried to make us believe.