Republican presidential candidate Marco Rubio, who has been dogged by questions over his personal finances, released portions of his tax returns Saturday, but the documents don't reveal details like which tax breaks he claimed or how much he gave to charity. -snip- Rubio’s release is aimed at increasing the pressure on GOP front-runner Donald Trump to produce his own returns, but the fact that Rubio only released partial returns may undermine his case. Meanwhile, Sen. Ted Cruz, who has also been demanding Trump produce tax documents, missed his own self-imposed deadline of Friday for providing his returns.