@AbbaS
You are wrong on two points
“45 senators have already voted that it is illegal to impeach anyone after they are out of office”
45 Senators voted to table a vote saying the the impeachment trial of a former President was Unconstitutional.
No vote took place to say it was illegal, Unconstitutional does not mean illegal. Illegal must be in contravention to a law, statute or regulation,
This is not the first time a former federal official has been impeached and tried after leaving office.