A Republican candidate interested in promoting a message of liberty wouldn’t see the non-payment of a certain kind of federal tax as a moral failing or proof of dependency and irresponsibility. On the contrary, he would have been pleased that the tax burden is so relatively light, and he would have understood that the lightness of that burden was a legacy of decades of his party’s policies. The Romney vision was that people ought to aspire to paying income tax, as if it were a marker of some sort of virtue, and that there was nothing else in what he was proposing that would cause them to support him.
There's something bizarre about watching a party -- the same party that crusaded for decades to move as many working-class citizens off the tax rolls as possible -- label non-taxpayers as being bad people.
Conservatism identifies excessive government as a problem for the poor and working-class. Why would we seek to further burden such citizens by demanding they send more of their earnings to a bureaucracy in Washington?
UPDATE: A commenter buys the Romney thesis:
Unless Americans are willing to have an ever expanding government and pay ever higher taxes, they will have to give up something that they receive from the government. People who do not pay income taxes are usually not willing to give up anything.
That idea would make sense were it not for the fact that working Americans (i.e. your pool of potentially dutiful income tax payers) contribute approximately 35 percent of the federal budget's revenue base via the payroll tax.
I'll embed a neat image of the breakdown below so it's perfectly clear.
And, for the record, the payroll tax caps at $110,000 a year.