In an earlier post I broke out the Senate's 33 to 22 vote in favor of the Clayton Compromise bill by party and region. I'm happy to report that I think I've discovered how to make the breakdown more readable:
|Free States||7 - 10||1 - 8||8 - 18|
|New England||1 - 4||1 - 5||2 - 9|
|Mid-Atlantic||2 - 1||0 - 1||2 -2|
|West||4 - 5||0 - 2||4 - 7|
|Slave States||18 - 0||7 - 4||25 - 4|
|Border/Mid||6 - 0||5 - 4||11 - 4|
|Cotton||12 - 0||2 - 0||14 - 0|
|Total||25 - 10||8 - 12||33 - 22|
Two things stand out. The first is the striking unanimity in favor of the bill among southern Democrats (18-0) and among both Democrats and Whigs hailing from the Cotton south states (14-0). Even John C. Calhoun voted in favor! Border and mid-south Whigs in contrast were almost evenly divided (5-4).
The second is the near unanimity against the bill among northern Whigs (1-8) and among New Englanders of both parties (2-9). Mid-Atlantic and western Democrats, however, were equally divided (6-6).
The northern vote is easier to explain. The nays appear to come almost exclusively from Conscience Whigs and Democrats who supported the Wilmot Proviso and would later become Free Soilers and Republicans (e.g., John P. Hale of New Hampshire and Hannibal Hamlin of Maine). They seem to have taken the position that they could not vote in favor because the bill left open the possibility, however slight, that the territories could wind up becoming slave territories.
Northern votes in favor of the bill came largely from Senators who were not wedded to the Proviso. A leading example is Daniel S. Dickinson of New York, who would later join the Hunker faction opposing the Barnburners, and later still a Hard-Shell, opposing readmission of the Barnburners back into good standing with the Democrats).
The southern vote is more difficult to comprehend. Since all deep south Senators voted in favor, one can only conclude that Senators such as John C. Calhoun believed that the bill gave the south everything to which it was reasonably entitled under the Constitution. The Constitution carried slavery with it of its own force and barred the federal government from legislating concerning slavery in the territories. This the bill studiously avoided doing.
Ironically, border and mid-south Whigs were divided (5-4), at least in part, because they were less doctrinaire on these constitutional questions. George E. Badger of North Carolina opined that the Constitution of itself did not establish slavery and that Congress did have the power to legislate concerning slavery in the territories. Joseph R. Underwood of Kentucky likewise expressed the view that Congress had the power to legislate concerning slavery in the territories.