These Southerners were proven correct in their fears when Lincoln trashed the Bill of Rights early in his first term. His declaration of war was the theme of "preserving the Union".
The 1st and 4th Amendments meant nothing and people were sent to prison for "discouraging voluntary enlistments" or because of a suspicion they were "disloyal". To borrow a phrase from James Madison, "I cannot put my finger on the part of the U.S. Constitution" that gives the President the power to suspend habeous corpus during wartime. For that matter, the Constitution does not give the President authority to call up 75,000 volunteers from some particular states to invade some other particular states, or another country.
There were thousands of brave Northerners who questioned the Constitutional intergrity of the adminsistration and some of them were Congressmen and federal judges. The election of 1864 was an endorsement of Union over the Constitution and the legacy of the War seems to have settled the matter for all time. No need to bring up the long ignored 9th and 10th Amendments again.