Can a state charge, especially one post conviction be moved to a federal court?
Isn't that contrary to the constitution?
Post conviction, I understand the route would be to try to get the US Supreme Court to hear an appeal from the State's highest court.
Given the way Trump has stacked the SC, it would not be surprising to have the likes of Alito and Thomas come up with some convoluted argument which says either the original matter should have been heard in Federal court, or to dismiss entirely whatever charges were taken there. Presidential immunity comes to mind.
Trump has tried to get his New York hush money trial moved to the Federal Court, but has so far failed.
Pre conviction, a State case could be heard by a Federal Court if there is Federal jurisdiction. For example, Trump's former Chief of Staff Mark Meadows, has tried to get his charges for involvement in the efforts to overturn the 2020 election, moved to Federal Court. The charges made against him in Georgia are the ones which come to mind. This was I believe because he thought a Federal court would be more sympathetic.
His argument for a Federal hearing was that his activities to overturn the election were under the colour of his role as Chief of Staff, which was a Federal position. This was rejected by the SC.