The government already solved this with the FDIC deposit insurance, and it is funded by the banks.

"...The FDIC is not supported by public funds; member banks' insurance dues are its primary source of funding. When dues and the proceeds of bank liquidations are insufficient, it can borrow from the federal government, or issue debt through the Federal Financing Bank on terms that the bank decides." - https://en.wikipedia.org/wiki/Federal_Deposit_Insurance_Corp...

The federal government should provide electronic money accounts with capabilities to perform transfers as infrastructure. Perhaps this will cause some richer people to politically support this.

I don’t see anything in my copy of the constitution about subsidizing demand deposits.