They lost me well before "maverick." He opposes all LGBT equality and he picked a VP who does as well. The only thing he didn't do was go to the extreme of supporting the FMA, but he let that amendment enter the party platform.
The real reason for this endorsement's pretty obvious, though: John McCain gave the LCR's access. When it comes to political advocacy groups, that's the best thing he can give.
The Human Rights Campaign goes right to the issues and concedes no points:"John McCain claims to be a maverick who breaks with his party, but on matters of LGBT equality, he's shown that he's anything but. He actively campaigned for a constitutional amendment that would have banned marriage and domestic partnerships for same-sex couples in his home state of Arizona. He went so far as to appear in television commercials for that campaign, is now supporting an amendment to strip marriage equality from California couples and has said that he would vote for a federal marriage amendment if laws already banning marriage equality were to be struck down by federal courts. Sarah Palin has also supported bans on marriage and even domestic partner benefits in Alaska."
What they don't mention, but what I hear privately and in the open at GLBT events on a regular basis, is that this presidential race matters because of the Supreme Court. GLBT leaders are concerned that the Court that decided Lawrence v. Texas will change dramatically in the next presidential term. And those changes could be in place for twenty plus years. It is in the coming era that the conflicting patchwork of federal and state laws on marriage and civil unions will be adjudicated. As more states join Massachusetts and California in marriage equality, how will full faith and credit and equal protection challenges to the Defense of Marriage Act be decided? Marriage is certainly not the largest issue looming in the minds of voters and it's not the only issue of concern to the GLBT community, but it's a big one. And this race could be decisive in determining the timetable for equal rights in this country.