This is an interesting post:
The main target of Republican ire on the zero-tax front isn’t the elderly or the temporarily unemployed. It’s poor people. And one of the reasons that so many poor people pay no income tax is the Earned Income Tax Credit, which can reduce your tax bill to zero or less. To qualify, though, you need a minimum income (i.e., you need to have a job), which makes the EITC an incentive to work — and this is why it’s an anti-poverty program that Republicans used to support.
Roughly speaking, then, Republican support for the EITC has steadily declined since the mid-80s, and the majority of the party has been actively opposed to it since the mid-90s. So I don’t think you can really blame the current antipathy toward EITC on the historical ignorance of modern Republicans. This all started 30 years ago, when Republicans were still keenly aware of both the program’s origins and its conservative policy underpinnings. They just decided they didn’t like the idea of giving money to poor people anymore. Now they’ve gone even further, and Mitt Romney’s echo of his wealthy donors’ disdain for the non-taxpaying poor is merely the next step along a logical path. Here’s the path:
1975-1985: Support for work-oriented anti-poverty programs like the EITC.
1985-1995: Mixed emotions toward EITC.
1995-2005: Opposed to EITC.
2005-present: Not just opposed to EITC, but actively in favor of making the poor start paying income taxes.
I think there are probably two reasons for the shift. One is given by a commenter:
right-wingers discovered that screeching about huge numbers of people not paying income taxes was the most fantastic talking point in the history of the universe. It would be far too good to give up, certainly for anything resembling either a practical or principled position.
Another is that Republicans probably took this position as a different way to help the poor to counter LBJ’s War on Poverty. As the years have gone on, though, Democrats talk less and less about helping the poor, so Republicans no longer needed a program for the poor they could support. And so they no longer support EITC.