Exactly. Right now, those 13 only mean that some 3-Judge panels will give us some favorable rulings. But important cases will always be pushed to a larger panel or en banc, where the liberal majority will rule against us. We need at least 5 more appointments, and more if we want it to survive the next liberal POTUS.
It’s now 13 R to 16 D. So we need only TWO more appointments that replace D’s. Then it would be 15 R to 14 D. Conservatives would be the majority.