The GOP claims that the payroll tax cut should not be extended because not only was it original passed with the idea that it was temporary but that it was assumed that it was going to be temporary. However, as for the Bush tax cuts, which while they were also passed with the idea that they were only temporary since most Republicans ASSUMED that they would eventually be made permanent that they are not being hypocritical.
So it's Obama's fault that he and the Dem's ASSUMED that the payroll tax cut would be temporary when they said they were temporary. It would have been a different ball game if they had just done what Bush and the Republicans did, while it was true that they SAID that the tax cuts were temporary, they had assumed all along that they the wouldn't be. See, that's how it done.
http://www.huffingtonpost.com/2011/11/27/jon-kyl-payroll-tax-cut-extension_n_1114992.html