I don't know about those people who do accuse the Cheneys of whatever; it's pure crap. They love their daughter, they quite evidently accept her sexuality. But the fact remains that they are in a party that as a whole, does not accept it and they choose to 'graciously abstain' from commenting on the issue of how to codify homosexuality and its trappings in the law.
I believe this was the same argument made in the pre-Emancipation South, pre- women's sufferage, and anything else where a certain segment of the population wants to deny people of their rights and dignity. 'Well, if you move to X, you can have your rights' does not cut it. Civil unions are a great compromise; it's worked in VT and it's done as an issue, no more bally-hoo about it. Bush even said he supported CU's during the campaign. This whole issue continues in the undead only b/c people on both sides see it as one they use to motivate their 'base' to the polls so they can get elected or pass other crap.