New analysis says Rubio's tax plan is still overwhelmingly tilted towards the wealthy

The Tax Policy Center (TPC) released its take on Marco Rubio's tax plan on Thursday. They concluded it would overwhelmingly benefits top earners the most, largely because it greatly reduces taxes on wealth income. And maybe eliminates them entirely — it's unclear.

Which brings up another point the analysis highlights: details matter.

For instance, Rubio's plan makes heavy use of tax credits, which allow filers to eliminate a set amount of their final tax liability. But what if the tax credit eliminates all of their tax liability, and there's still some of the credit left over? If the credit is refundable, the filer gets the remainder back from the government. If it's not, they don't.

How refundability would work has massive implications for who Rubio's tax plan would help the most. The TPC said Rubio's people didn't provide them the necessary details, so they went with assumptions based on the Rubio campaign's assertion that "our reforms would not create payments for new, non-working filers." Here are their results, in terms of the percent change in people's after tax income. ("Lowest quintile" means the bottom fifth of workers, "second quintile" means the second-lowest fight, and so on.)

(Graph courtesy of the Tax Policy Center.)

TPC found the plan would also massively reduce government revenue. Since Rubio has promised both a balanced budget and an increase in military spending, this implies enormous reductions in spending elsewhere.