Trump's exclusion of an oft-touted Social Security proposal will be highly unpopular but is absolutely necessary.

The Social Security Administration this week sent out an email to many Americans celebrating the passage of President Donald Trump’s domestic policy bill, and touting the measure’s tax relief for seniors, in a move that analysts said strayed from the agency’s typically apolitical nature.

The emails say nearly 9 in 10 Social Security beneficiaries won’t pay income taxes on their benefits in the future. But the Trump tax law did not directly address Social Security.