For the record, I DO see plenty of liberal groups flagrantly violating the law, and your claim about attitude toward paying taxes is a clever red herring, because EVERY organization that claims tax-exempt status is claiming the same thing with respect to what the IRS has jurisdiction to investigate: "WE, our organization, should not have to pay taxes." There are countless liberal activist organizations making that claim.
To be excused from taxes, as every such organization regardless of their politics is claiming they should be, an organization is required to obey certain rules that aren't supposed to depend on the specifics of their politics. Things such as actively trying to get a particular candidate elected explicitly violate the rules and, by law, should cost an organization its tax-exempt status. Yet Obama's IRS enforcers have had no objection to tax-exempt "community organizers" going door to door on election day to "get out the vote" but, for some reason, only knocking on doors of registered Democrats.
Regardless of any political theories about taxes in general, which the IRS is not empowered to take a position on, these organizations are all the same in claiming that THEY themselves don't have to pay them. The IRS is supposed to investigate such claims, and yet while liberal organizations were able to go as far as actively encouraging individual registered Democrats to vote in the specific election being held that very day (in which only one candidate was from the party of everyone being encouraged to go vote) without fear of scrutiny by Obama's IRS, any organization that so much as used the term "liberty" in its name was, it turned out, risking audits, time-consuming scrutiny of their activities, potential denial of tax-exempt status because they might get involved in politics, etc. We can't have political activists claiming tax-exempt status getting involved in politics, right? Well, it turned out to depend entirely on their politics, not on the nature of their activities.
ALL organizations claiming tax exempt status are making the same claim with respect to paying their own taxes, and your claims regarding your own tax liability is the ONLY thing the IRS is empowered to scrutinize. To claim that, among those groups, the ones who believe that "WE don't have to pay at all, and OTHERS should be taxed less" are more likely breaking the law than those whose position is "WE don't have to pay at all, and OTHERS should be forced to pay more for our agenda" is ridiculous.