Dissent is not illegal, but inducing soldiers to desert or draftees to evade conscription is illegal. I believe that is what Lincoln meant by his quote.
What about soldiers who are underage minors and are legally unqualified to enlist at their present age? As Murphy's case shows, Lincoln was pretty darn enthusiastic of forcing kids of that situation into service!
It seems you're talking about a different set of cases then? Lincoln cannot use an egregious example which isn't applicable for justification no more than Bush can detain those who run red lights at Guantanimo Bay, right?
As usual, bass ackwards. Advocacy, whether to teach the duty, necessity, or propriety of violence, or the doctrines of criminal syndicalism, is lawful. Advocacy, unless to incite to imminent lawless action, is lawful.
Brandenburg v. Ohio, U.S. Supreme Court, 395 U.S. 444 (1969)
Measured by this test, Ohio's Criminal Syndicalism Act cannot be sustained. The Act punishes persons who "advocate or teach the duty, necessity, or propriety" of violence "as a means of accomplishing industrial or political reform"; or who publish or circulate or display any book or paper containing such advocacy; or who "justify" the commission of violent acts "with intent to exemplify, spread or advocate the propriety of the doctrines of criminal syndicalism"; or who "voluntarily assemble" with a group formed "to teach or advocate the doctrines of criminal syndicalism." Neither the indictment nor the trial judge's instructions to the jury in any way refined the statute's bald definition of the crime in terms of mere advocacy not distinguished from incitement to imminent lawless action.Accordingly, we are here confronted with a statute which, by its own words and as applied, purports to punish mere advocacy and to forbid, on pain of criminal punishment, assembly with others merely to advocate the described type of action. Such a statute falls within the condemnation of the First and Fourteenth Amendments. The contrary teaching of Whitney v. California, supra, cannot be supported, and that decision is therefore overruled.