We have the "Can they do X?" discussion about 47 times a second in these political discussions.
Here's the simple truth. If there is no formal, in writing, already used so it was established as precedence rule saying they can't do it with formal, in writing, already used so it was established as precedence consequence for doing it, they yes they absolutely can do "X" no matter what "X" is.
"Will they" is still in the air, but "Can they" absolutely isn't.
The last few years have torn the scab off and revealed the ugly wound that sooooooo much of American politics was based on the honor system, and that requires all sides to have standards or at the very least some sense of shame.