Well, here's the thing. The fact-checkers are simply unaware of the truth--or falsity--of the statements at issue, and so are you, and so am I.
Here is what Reid originally said:
"His poor father must be so embarrassed about his son," Reid said, in reference to George Romney's standard-setting decision to turn over 12 years of tax returns when he ran for president in the late 1960s.To lie, according to the OED, is "to make a false statement with the intention to deceive." (Other definitions at the link refine it, but are broadly consistent.) If Reid did have the conversation with his source, then he is not guilty of that. He may be guilty of suggestio falsi--here, by using a true statement that contains within it a statement he does not believe to be true, but which he honestly reports as having been made to him, but he is not lying. Indeed,even his critics tacitly acknowledge--they raise the bar, requiring him to prove not the conversation with the source, but the accuracy of the source's information.
Saying he had "no problem with somebody being really, really wealthy," Reid sat up in his chair a bit before stirring the pot further. A month or so ago, he said, a person who had invested with Bain Capital called his office.
"Harry, he didn't pay any taxes for 10 years," Reid recounted the person as saying.
"He didn't pay taxes for 10 years! Now, do I know that that's true? Well, I'm not certain," said Reid. "But obviously he can't release those tax returns. How would it look?
"You guys have said his wealth is $250 million," Reid went on. "Not a chance in the world. It's a lot more than that. I mean, you do pretty well if you don't pay taxes for 10 years when you're making millions and millions of dollars."
As Kessler admits, "Reid has refused to provide any evidence, except for the (unproven) fact that someone called him up and told him something that may be true — or simply a rumor." (My emphasis.) Politifact hinges its analysis on the improbability (not impossibility!) of the information provided by Reid's source, as does Kessler. In other words, they hold him to the very part of the statement he said he could not vouch for--that Romney had literally paid no income tax for ten years.
What Harry Reid is guilty of is what my late grandfather would have called "dirty pool." He is upping the pressure on Romney to release the tax returns by a sort of low-level psy-op--almost a con trick. Note that Reid didn't just try to give the story legs, he attacked Romney emotionally, invoking his father. (Surprisingly, that part of Reid's attack didn't draw much condemnation.) It's manipulative. It's tricky. It may even include a lie.