The greatest value of the film Lincoln is in how it demonstrates that there wasn't necessarily any permanence to the Emancipation Proclamation itself. A Constitutional Amendment was needed to finish the work. And when that failed to finish the work of ensuring equal citizenship the Constitution was amended again, and again.
I must sigh when I measure what Lincoln, his cabinet, and Congress accomplished then with the charade that these debt ceiling negotiations have been. Now our politicians can't seem to reach across the aisle on matters of financing the operations of government. Lincoln and Congress in their day struggled also to create 11th hour deals (wait, last night's deal wasn't really 11th hour . . . it was more like 12th hour). The Wade-Davis measure was so last-minute is was pocket-vetoed by Lincoln. The 13th Amendment itself passed the House of Representatives in the last days of a lame duck Congress. Those certainly seem like more noble arguments necessitating last-minute compromise than how much money our government can borrow, or whether it will be household incomes higher than $250,000 or $450,000 that will be subject to a rise in taxes amounting to a few percentages of a point.
But there wasn't anything last-minute regarding the Emancipation Proclamation. It was drafted in August. It was promulgated in September. It took effect on New Year Day. Its full promise took a century to deliver (and some might argue it wasn't fully delivered).