There's that old saying: "People who live in glass houses shouldn't throw stones." Apparently, when it comes to Medicare, the Democrats have forgotten this sage advice. As soon as Ryan was named as Romney's V.P. pick, they went after him on the basis that he would change Medicare. This was stupid on their part, because, as we all know now, Obama and the Democrats have, themselves, "changed Medicare as we know it" by draining $716 billion from it to pay for ObamaCare.
The cat's out of the bag and, believe me, there's no putting that cat back. From now to November, the Republicans should just hammer Obama on his handling of Medicare. Medicare is already in trouble because of funding and is expected to be insolvent in just 12 years, and taking $716 billion away from it will just shorten that time.
For Reference: Trustees: Medicare Will Go Broke in 2016, If You Exclude Obamacare's Double-Counting: http://www.forbes.com/sites/aroy/2012/04/23/trustees-medicare-will-go-broke-in-2016-if-you-exclude-obamacares-double-counting/