The proofs that he abandoned the party were:
1. Agreed to buy LA purchase arguing -
At that time, the members of democratic republican party believe that the purchase was unconstitutional lands can be added to US because presidential power to make treaties
2. Tried to block the federalist judges appointed by Adams
At that time, the democratic republican party tried to support the appointment.
3. Repealed Alien and Sedition acts, and released those jailed under them
At that time, the majority members of democratic republican party denounce the alien and sedations acts