Voldemort is one of the most powerful dark wizards ever in the Harry Potter universe. He has a variety of powerful dark magic spells at his disposal.
Voldemort’s use of dark magic means that, generally speaking, he would not be able to cast a Patronus charm. Patronuses are a form of protection against dark magic, so it would not make sense for a wizard to use a Patronus charm if they were already wielding dark magic.
It is important to note that Patronuses are not only a form of protection. They also represent a connection to a person’s positive emotions and memories. In order for someone to cast a Patronus charm, they must be able to tap into the positive emotions associated with their happiest memories. This would be a difficult task for Voldemort, as he is not known for having a lot of positive emotions or memories.
It is also worth mentioning that Voldemort is a character who is dead, but not actually dead. This means that he is neither fully alive nor fully dead and is instead in a state of limbo. This raises questions about whether Voldemort would even be able to cast a Patronus charm, as it is not clear whether someone in this state would be able to access their happiest memories.
Furthermore, Voldemort is a Horcrux. This means that he has a piece of his soul split off and stored in a physical object, which is a form of dark magic. This could create an additional barrier to Voldemort’s ability to cast a Patronus charm, as it is unclear whether a piece of soul in a physical object would be able to access the positive emotions associated with a Patronus.
It is therefore unlikely that Voldemort would be able to cast a Patronus charm, due to his use of dark magic, lack of positive emotions, ambiguous state of being, and existence as a Horcrux.