social security can be saved if
1. the ceiling on taxable income is raised or removed. currently income that is above 110,000 is not taxed. That means a person making a billion dollars pay the same amount of social security taxes as someone making 110,000 dollars. since the rich are getting richer, they are depriving social security of funding, especially if they make their money by suppressing worker wages.
2. minimum wage increased, because the more money people earn, the more social security and medicare tax they pay.
3. permit immigrant workers to come to the USA to fill jobs that Americans either cannot or will not fill, since they will pay social security taxes.
Trump and the Republicans oppose all of these solutions. Therefore they are trying to kill social security. Democrats want to save security. They support all 3 solutions above.