It’s becoming pretty clear how Republicans plan to defend their budget. They’re going to lie about it.

I’m referring specifically to the way they and their supporters describe the budget’s treatment of Medicare and Medicaid – and how those proposals compare to the changes enacted via the Affordable Care Act. I wrote about these last week, when self-proclaimed (and almost universally discredited) health care expert Elizabeth McCaughey* made these arguments in the Wall Street Journal. But versions of them have been popping up ever since--most vividly on Sunday, when Florida Republican Senator Marco Rubio appeared on the “Meet the Press.”

Here’s what Rubio said:

The Ryan plan doesn't cut Medicare. Actually, it increases funding in it. And the only people in this town that have voted to cut Medicare are the people that supported Obamacare, that cut half a trillion dollars over the next 10 years out of Medicare and is using it to fund a healthcare experiment somewhere outside of Medicare. The only people in this town that have voted to cut Medicare spending are the people who voted in favor of Obamacare. That's a fact. And so the truth is the people.

Sigh. This is pretty much the opposite of the truth. Yes, the Affordable Care Act reduces spending on Medicare. But it does so gradually, by establishing a long-term goal of allowing the program to grow at the same rate of gross domestic product plus one additional percentage points--that is, GDP+1. And it’s a goal in the truest sense of the word. If the program’s starts growing at a faster pace, there are mechanisms to slow it down but not necessarily to get it all the way back to GDP+1.

The Republican budget, by contrast, would hold the cost growth of Medicare to the consumer price index, or CPI. CPI grows considerably slower than GDP, let alone GDP+1, so that's no small thing. The Republican budget would also enforce this target rigidly, by handing seniors vouchers whose value is set by a fixed, pre-determined formula. At the same time, the Republican budget would dramatically reduce the federal investment in Medicaid, on which so many of the elderly rely for supplemental coverage and/or long-term care, particularly nursing homes.