That's odd. That would seem to indicate that there is some sort of permission issue with that file or the folder that it is in. If your user account is a system administrator then you should have rw permission on the file and should be able to trash it. There should be not file in you own user Library that you cannot delete.
Is there any message when you drag it to the trash?
If after deleting all the files can you download a fresh copy of the TurboTax .dmg file and reinstall that (without state) and open that? Perhaps there is a problem with that particular state file but if you delete the Application Support files then that should remove the state so the TT application should run if installed without the state (you will not be able to open your .tax2019 file without the state but should be able to start a new tax return as a test).
Be sure to clear the trash and restart the Mac after doing the uninstall before re-installing.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
