The subsidies are paid for by taxes on investment earnings of rich Americans. They do not increase the deficit. That is a Republican myth. But if the ACA is repealed (including the taxes), the Republican plan will definitely explode the deficit. They don't mention revenue to pay for their tax credits. But Republicans, for all their big talk, not only never balance a budget, but when they get the power they have now, they blow up the deficit massively. That process is underway right now.