For what it's worth the English term is filibuster. A government supportive of the filibusters wouldn't necessarily have to be dominated by the South, but it's certainly much more difficult if it isn't. The filibusters were, as you point out, primarily popular in the South because the territories they acted in were generally seen as favorable to slavery and would be open to it if acquired by the United States. That hurt their popularity in th eNorth because it made them seem like an extension of the slave power trying to seize more territories for slavery. Additionally, the Filibusters were awful for American relations with Latin American nations and for America's image abroad generally.
So, part of getting government support for filibustering is goiing to be having a government that doesn't mind a terrible reputation in Latin America and is interested in expanding American influence and control in the Americas. Territorial expansion tended to be more popular in the South than in the North, though it was by no means a clear cut distinction. So a non-southern dominated government would need some reason to want more territory and influnece in Latin America. That could be plain old nationalism but I'm not sure if that would be sufficient in and of itself.
My opinion is that a government more dominated by the South and slavery is the best path to a government that supports filibustering. Possibly more slave states would be the way to go to achieve this as it would increase their control of the government and increase the impetus to aquire more slave territories. Both Illinois and Indiana could potentially have legalized slavery as terriotries or states. That might be the extra impetus needed. However, the risk is that additional slave states eliminates the percieved need on the part of the South for more territories in which to create slave states to balance out the free states. So it's a balancing act of giving the South enough additonal influence to support the filibusters but still making them feel outnumbered by the free states. And then on top of that making the government want additonal territory enough to back them. It's tricky, but not impossible.