dead man walking
US /dɛd mæn ˈwɔkɪŋ/
UK /dɛd mæn ˈwɔkɪŋ/

1.
a person who is certain to experience something bad or fail soon, even though it has not happened yet
:
•
After that disastrous presentation, the CEO was a dead man walking.
•
The politician, embroiled in scandal, was widely considered a dead man walking.