It wasn't until the first sentence of your lengthy response that you said something false.
Northerners could have refused to establish a constitution that provided for slavery in the union. But in 1787 Northerners were not willing. They were not ready. They were not able. Northerners actually did something quite different that what you suggested. They voted to embrace slavery into the U.S. constitution.
In 1861 Northerners could have introduced, and voted on, a constitutional amendment to abolish slavery - if they were willing, ready and able. History records they were not.
And all the time slavery was legal in the U.S., Northerners cheerfully made lots of money off of the practice. Perhaps every time a Northerner cashed a large slavery dividend, they said, "I accept this money under protest."
Sadly FRiend, of charm you have none, but happily your wit exceeds your charm, by half.
jeffersondem: "Northerners could have refused to establish a constitution that provided for slavery in the union.
But in 1787 Northerners were not willing."
The rare Southern slave-holder like George Washington said that he would sacrifice slavery for Union, but most other Southerners would not.
They made clear that without slavery there would be no Union, period.
Abolitionist Northerners accepted that condition, believing in 1787 that slavery was a dying institution to be accepted or abolished by states, not by Federal government.
"In 1861 Northerners could have introduced, and voted on, a constitutional amendment to abolish slavery - if they were willing, ready and able.
History records they were not."
Actually, Union enforced emancipation did begin in 1861, soon after the Confederacy started & declared war on the United States.
Beginning in August 1861 various acts of congress and Presidential orders emancipated different groups of slaves such that by the time of the 13th Amendment in 1865, only a small percentage of the South's four million slaves had not already been freed.
"And all the time slavery was legal in the U.S., Northerners cheerfully made lots of money off of the practice.
Perhaps every time a Northerner cashed a large slavery dividend, they said, 'I accept this money under protest'. "
What you don't "get" is: the Southern Democrat Slave-Power was closely allied politically with their Northern Democrat business partners, who fully understood and sympathized with Southern ideals.
So, when the Deep South first declared secession, many New Yorkers not only cheered them on, they wanted to join and secede too!
And for most of the years from 1788 through 1860 that political alliance of Southern Slave-Power Democrats to Northern Big City Democrats ruled in Washington, DC, to the satisfaction of both.
But no abolitionists were Democrats, they were all, if anything, Republicans and thus not part of the North-South Democrat alliance.
Republican abolitionists did not benefit directly from slavery, and thus were at odds with their Northern Democrat neighbors who did benefit.