How radical, in political terms, were the Radical Republicans?

Some other ways in which these men were radical include their
aggressive advocacy for the Civil War Amendments, the 13th, 14th and 15th, their desire for real
land reform in the South, and their belief that the Federal government had a responsibility to
pursue civil rights and equality in the social, political and economic terms of the
day.

Abolition of slavery was a foregone conclusion, yes, but
consider the 15th amendment, which gave black men the right to vote.  Considering where slaves
had been, legally, only a few months before, that was undoubtedly a radical
act.

Men like Senator Thaddeus Stevens, who supported the concept of
"40 acres and a mule" for each freed save family believed we should break up the southern
plantations and redistribute them to former slaves, an utterly radical
act.

Stevens also believed in the Conquered Province Theory, which
would have permanently denied southerners their citizenship, and run conquered seceding states as
though they were under martial law, as conquered provinces.  While this didn't pass, nor did 40
Acres and a Mule, they are certainly radical ideas for their time.