President Donald Trump renewed his demand for the Senate's "blue slip" tradition to be done away with and urged Senate Judiciary Chair Chuck Grassley to tell Democrats to "go to HELL."

It’s unclear whether the president could succeed in a legal challenge to the longstanding bipartisan tradition, which is an informal agreement between lawmakers not enshrined in law.

Speaking from the Oval Office, Trump slammed the blue-slip process, which is not a formal Senate rule but a bipartisan tradition dating back more than 100 years. Trump complained the tradition has allowed Democratic senators to veto his picks for vacancies in blue and purple states.