Au contraire.
Section 8: "To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions
Of course, when the militia is suppressing insurrections it is under the command of the President. There is nothing in the Constitution to imply the president has fewer war powers to suppress an insurrection than to repel an invasion.
After Lousiana was captured by Federal troops, slaves were not freed.
The EP freed all LA slaves except those in the city of New Orleans and in 13 named parishes at the time under federal control.
Lincoln wanted it both ways: the Southerners were "states" when he wanted them to be, and a foreign power when he didn't.
As do CSA apologists. If the CSA was a foreign government, as it claimed and fought to uphold, it had no rights under the Constitution. The EP was fully valid as a means of injuring the foreign enemy. If the states were still part of the US, they were quite obviously in insurrection. Look, the Constitution is a very flexible document, but it isn't flexible enough to stretch around a civil war. Any attempt to do so results in a variety of legal fictions.
"war powers" - is that what Licoln exercised when he placed the entire state assembly of Maryland in prison in Fort McHenry?
Reference please. My research indicates that a grand total of 26 MD state legislators were imprisones at different times during the war, not the whole body. There was discussion of doing so within the government, but it wasn't carried out.
http://www.abrahamlincolnsclassroom.org/Library/newsletter.asp?ID=108&CRLI=156