What was the reason the Radical Republicans opposed President Johnson's Reconstruction plan?

The Radical Republicans opposed Lincoln's plan because they thought it too lenient toward the South.

Explanation:

Radical Republicans believed that Lincoln's plan for Reconstruction was not harsh enough because, from their point of view, the South was guilty of starting the war and deserved to be punished as such.

the new right felt that federal welfare programs lowered taxes and strengthened the traditional family