Name one act of the lincoln administration opponents considered unconstitutional and explain their reasoning

Abraham Lincoln's position on slavery is one of the central issues in American history.

Lincoln often expressed moral opposition to slavery in public and private. Initially, he expected to bring about the eventual extinction of slavery by stopping its further expansion into any U.S. territory, and by proposing compensated emancipation (an offer Congress applied to Washington, D.C.) in his early presidency.

You didn't provide possible answers, however, the sturm un drang movement centered on rejection of all things traditional, aesthetic, rational, related to the enlightenment period, or anything similar. They wanted to completely break themselves free from all tradition, so if anything fits the description then that is your answer.