Please helppp it’s important

Draw conclusions  why might a cause like italian unification successfully draw people of very different backgrounds together?  

After the supreme court’s ruling on the dred scott case, many people in the north believed that a. slavery might become legal everywhere. b. slavery might be banned everywhere. c. formerly enslaved people would move to the north. d. formerly enslaved people would stay in the south.

How is the president involved in the process of bills becoming laws?