Actually, the US shares very little with Greece.
The biggest problem in Greece is that most of the economy is dominated by a few extremely wealthy families, like the Onassis and the Niarkos, and these people pay very little or nothing in taxes and the Greek government cannot enforce the tax laws well on anyone other than public employees, who are a huge portion of the middle class. The poorest people in Greece have cash businesses and do not declare their income accurately, either. All Greeks recognize that the system is broken and no one wants to pay for the many scofflaws, who comprise a majority of the country.
It is simply ignorance that causes the ratbag right to compare the US to Greece. The US is NOT AT ALL like Greece.
The US controls its own currency: Greece does not, so the potential solutions are also quite different.