Morill tariff was passed only because the rebels had left the Senate. Without the rebellion, it wouldn’t have passed.
With the rebellion, added funds were needed to suppress treason.
It looks as if you already know the true facts on this subject, but like to bait to promote a little debate. Well, let's not disappoint you:
Here is a little known cause of the Secession.....Congressional Reapportionment Threatened the Union
On December 12, 1860 speaking before the Senate, before any state had seceded, Sen. Louis Wigfall revealed his opinion on future equal representation as provided by the US Constitution:
“Tell me not that we have got the legislative department of this Government, for I say we have not. As to this body, where do we stand?
“Why, sir, there are now eighteen non-slaveholding States. In a few weeks we shall have the nineteenth, for Kansas will be brought in. Then arithmetic which settles our position is simple and easy.
“Thirty-eight northern Senators you will have upon this floor. We shall have thirty to your thirty-eight. After the 4th of March, the Senator from California, the Senator from Indiana, the Senator from New Jersey, and the Senator from Minnesota will be here.
“That reduces the northern phalanx to thirty-four...There are four of the northern Senators upon whom we can rely, whom we know to be friends, whom we have trusted in our days of trial heretofore, and in whom, as Constitution-loving men, we will trust.
“Then we stand thirty-four to thirty-four, and your Black Republican Vice President to give the casting vote.
“Mr. Lincoln can make his own nominations with perfect security that they will be confirmed by this body, even if every slave holding State should remain in the Union, which, thank God, they will not do.”
There was no doubt that the election of the Republicans meant that Congressional reapportionment would cause the South to lose itself to the North.
The Morrill tariff was but one major change that was about to be forced on the South.