On the left, pundits counter by saying there are more taxes than federal income taxes. For example, everyone with a job pays federal payroll taxes.
For example, here is Jon Chait, citing and debunking the rights point's about who pays taxes.
Are right leaning pundits deliberately trying to pull a fast one, hoping that people will gloss over the modifiers "federal" and "income" and think the stats apply to total taxes?
Maybe. Couldn't put it past them, though Chait (and his source, Emmy winner Leonhardt) do a poor job making their case.
But who pays federal income taxes is an important issue because we are debating raising them! If everyone votes and the median voter doesn't pay federal income taxes, then there is little direct cost to the majority in voting higher tax rates.
That, I think, is the important public choice issue here, and it makes question of who pays federal income taxes is important in it's own right, irrespective what other taxes exist, given that it's the federal income tax we are proposing changing.