1 in 19 Americans are on SSI and you say its hard to get. Read it again, Apparently it is NOT hard to get.
SSI and SSDI are two highly different critters all together. The standards for SSI are low. You don't have to be disabled just poor. SSI is welfare.
Social Security Disability Insurance has a much higher qualification standard and burden of proof. It sometimes takes years to get it and most give up or die first. SSI is immediate. The senator was not smart in connecting them together because they aren't.