The Gilder Lehrman Institute of American History has put up several rather concise series of commentaries from various historians addressing topics in American history. Here, Allen Guelzo of Gettysburg College explores how Abraham Lincoln viewed slavery, the justification for the Emancipation Proclamation, and how people then and later found fault with the Emancipation Proclamation.
In the first video Guelzo explores Lincoln’s attitudes toward slavery and its abolition, finding a basic consistency in his opposition to slavery.
In the second video Guelzo examines the basis of the Emancipation Proclamation as a manifestation of presidential war powers.
The third video addresses how over time criticisms of Lincoln’s issuing the Emancipation Proclamation changed from having done too much to having done too little.
Crossroads 
I watched the third video on criticisms of the EP. It seems to me that Guelzo overemphasizes the critical reaction of the EP going too far when it was first issued. Not that there wasn’t a strong reaction of that sort, but there was also a strong reaction from Radicals who argued that it did not go far enough – the very criticism that Guelzo says only came later.
Missourians were locked in a battle between Conservatives and Radicals over emancipation. Charles Drake and B Gratz Brown lambasted Lincoln for not including Missouri in the EP. I think this article gives a good description of this:
http://www.abrahamlincolnsclassroom.org/Library/newsletter.asp?ID=64&CRLI=144
Weren’t Radicals from other states, like Stevens, Sumner, etc., also critical of the EP for not going far enough?