Here is a little of the story of Clement Vallandigham, a Democrat from the 1870's that would fit in with the D's today.

Vallandigham was opposed to the war, the draft, Lincoln's suspension of habeas corpus, the Emancipation Proclamation, and every other step taken by Lincoln to bolster the power of the Union, the federal government, and the presidency.

Vallandigham lashed out at Lincoln. "I see more barbarism and sin... in continuing this war" he wrote, than in "the sin and barbarism of African slavery." As he gained national attention as a critic of the war

Vallandigham criticized Lincoln for Executive Order #38, whipping the crowd into a frenzy, and prompting General R. L. Burnside to order Union soldiers to arrest Vallandigham and bring him before a military tribunal

Here is the full text:
http://home.comcast.net/~tom.mayer/clementvallandigham.htm

And it continues with this on how President Lincoln dealt with the situation:

In the Vallandigham case, Lincoln conceded that if the only reason for the arrest was the words he spoke, then the arrest was wrong. However, Lincoln argued that Vallandigham's intention was to undermine the armed forces and destroy the military force of the the Union. With a brilliant sentence, Lincoln set out his policy on Free Speech in wartime, and provided one of the major precedents that would help decide the major Free Speech Cases in the twentieth century: "Am I to shoot a simple-minded soldier boy who deserts, while I must not touch a hair of a wily agitator who induces him to desert?" Thus Lincoln, who was a fierce champion of constitutional rights, read the law to mean that certain speech was objectionable in wartime if (a) the speech was designed to cause people to break the law and (b) the speech was likely to interfere with the war effort - though this does not necessarily mean that criticizing or dissenting from the war was punishable by law.

Here is the link to the second half:

http://home.comcast.net/~tom.mayer/abrahamlincoln.htm