Final answer:
The fundamental opposition to Andrew Johnson's reconstruction policy was from the Radical Republicans. They believed in greater federal control and protecting the rights of freedpeople.
Step-by-step explanation:
The fundamental opposition to Andrew Johnson's reconstruction policy was primarily from the Radical Republicans. They believed that the federal government should have a greater say in the process of reconstruction and wanted to ensure that real Unionists controlled the process and protected the rights of the freedpeople. They contended that the southern states had committed by seceding, and therefore, only Congress had the right to set the terms for readmission to the Union.