Justices could still change their minds before the final ruling, but doing so could undermine confidence in the Supreme Court's ability to remain apolitical.
The Supreme Court's move rightward makes the Chief Justice's role less relevant, but don't underestimate Roberts' ability to maneuver.
She was once told the "dogma lives loudly within you" by a senator.
The Supreme Court nomination process has gotten more contentious since Kennedy was confirmed.
"When you elect presidents, this is what happens," Scarborough said about Trump picking a nominee to replace Justice Kennedy.
The justice has yet to hire new law clerks, instead telling applicants that he was considering retirement.
The Supreme Court will give its final last opinions of its term on Monday.
Kennedy is a conservative justice who sometimes joins the court's four liberals and often casts the deciding vote in close cases.
By violating the separation of powers, Senate Republicans are threatening democracy.