I can find the citations to the SCOTUS cases tomorrow if you really want to dig into this, but the short version goes something like this; in the 1960s, the Supreme Court essentially ruled that most states methods of applying the death penalty were unconstitutional under the 8th and 14th amendments; as a way of satisfying the constitutional standards set forth by SCOTUS every state has implemented a right to appeal in death penalty cases.
In that case your original assertion should not claim we have a Constitution that prohibits swift executions, (since we don't) rather we have a Supreme Court ruling that does.
I can find the citations to the SCOTUS cases tomorrow if you really want to dig into this, but the short version goes something like this; in the 1960s, the Supreme Court essentially ruled that most states methods of applying the death penalty were unconstitutional under the 8th and 14th amendments; as a way of satisfying the constitutional standards set forth by SCOTUS every state has implemented a right to appeal in death penalty cases.
In that case your original assertion should not claim we have a Constitution that prohibits swift executions, (since we don't) rather we have a Supreme Court ruling that does.