He was never a Senator. He was Congresscritter from Ohio who had already lost his bid for reelection in 1862 --- a full year before he pissed off the the US Army by calling for troops to desert their posts. In case you don't know, that is called Sedition and in times of war it can be punishable by death. He didn't make his call from the floor of Congress, by on the pages of the newspaper he owned in Ohio -- so much for the myth that every opposition paper was shut down. Criticism of the war and of Lincoln was quite common and not punished. There was no shortage of Northern newspapers critical of Lincoln and the war. But Sedition, and calls for treasonous activity were punished (as I wish they were today -- see the New York Times) .
Lincoln did not have him arrested --- that was the decision of local military commanders in Ohio. Lincoln, in fact ordered the Army to let him go free --- behind Confederate lines. They passed him over to Confederate troops in Tennessee, but they didn't want to put up with him either. They sent him on to Canada. And he didn't come back "after the war" he came back during the war to lead the Copperhead wing of the Democrat party who were so damn obnoxious that they doomed McClullen's chances. And in a state where democrats routinely won state-wide office, he never came even close to winning the Governorship.
Now where in the hell are you getting this 94% AWOL figure? Do you even know what AWOL means?
Ditto...the Sedition Act was done away with LONG ago.