The GOP congress would have every bit as much Constitutional authority to appoint a new president when Obama goes on vacation.
Come to think of it...
Let us say that two “liberal seats” on the Supreme Court open up at the same time in the middle of a jam-packed Supreme Court term and that there is a GOP President.
Then, a DEM-controlled Senate goes into pro forma session and the GOP Prez recess appoints two conservative justices. These justices then put the conservative side over the top on major cases [immigration, gay marriage, abortion, etc.].
The DEMS will be whining “no fair - no fair”, we were in “pro forma session” ...
Obama forgot the first rule of politics:
“Be careful what you wish for - you just may get it” ...
I guess congress can’t extend that payroll tax cut since they’re in recess.