Here's a decent explanation of the No Tax on Social Security bait-and-switch. It's from PBS, yet appears to be surprisingly correct (for them).
"President Donald Trump keeps saying that Republicans’ mega tax and spending cut legislation will eliminate taxes on federal Social Security benefits. It does not.
At best, Trump’s “no tax on Social Security” claim exaggerates the benefits to seniors if either the House or Senate-passed proposals is signed into law."
"But instead of eliminating the tax, the Senate and House have each passed their own versions of a
temporary tax deduction for seniors aged 65 and over, which
applies to all income — not just Social Security. And it turns out
not all Social Security beneficiaries will be able to claim the deduction. Those who won’t be able to do so include the lowest-income seniors who already don’t pay taxes on Social Security, those who choose to claim their benefits before they reach age 65 and those above a defined income threshold."
In other words, tax-wise, it has absolutely nothing to do with Social Security!
Trump says the Republican mega bill will eliminate taxes on Social Security. It does not