Rubio's move comes as several candidates for the Democratic Party's 2020 presidential nomination are discussing 'packing' the Supreme Court -- adding justices intended to nullify the perceived long-term conservative bias of the Court following Trump-era appointments.
A constitutional change to limit the Supreme Court to nine justices is unlikely: amendments are purposely hard.
Court-packing would not guarantee 'Democratic' or 'Republican' rulings: much depends on the case and how justices feel.
Packing the courts would likely increase their politicisation, and potentially slow their deliberative capacity.
If Trump wins a second term and Republicans keep the Senate, they will appoint further conservative justices.
If the Democrats win the White House and Senate in 2020, they might 'pack' the lower courts.
