The exact wording of the law actually stipulates a $6,000 tax deduction for individuals aged 65 and older, likely raising the number of seniors who won't pay taxes on Social Security to 88 percent. Currently, 64 percent of seniors already don't pay taxes on Social Security benefits.

Trump's flagship tax and spending law is expected to have a material (and adverse) impact on America's leading retirement program.

Republicans and Democrats have failed Social Security, and benefits Americans receive could be slashed in as little as 7 years if lawmakers don't act.