The Republican plan is simple, breath-takingly so- they want to steal the Social Security Trust Fund.
Their plan is to hand out $4 trillion in tax cuts over the next decade, using the money from SS to keep the government subsidies they rely on flowing- and when those funds are gone, to declare bankruptcy. They also intend to sit at the head of the table when the ensuing reorganization plan rewards some of the creditors and requires further payments by some of the debtors, so they can make sure that the lucky creditors who get paid are themselves, and the unlucky debtors who must continue paying are the not-rich taxpayers.
This is our money, which Boomers paid so our large cohort would not burden the next generation (we've funded SS through 2043), but Republicans see no reason they shouldn't take it, considering that destroying our democracy is a goal they have shouted from the rooftops- so why not just take the money and bankrupt us?
It's a business model Republicans have used for years- acquire a healthy corporation, extract every liquid and semi-liquid asset, and dump the carcass, leaving the less alert shareholders holding the bag. Now they think they're poised to commit the largest theft in all of human history. And it's not as though, on a smaller scale, this kind of thing hasn't worked before.