I honestly doubt you heard him “endorse” anybody. He may have urged us to punish the republicans in 2004, by voting against them. As far as this year, all I’ve heard him say is that he, personally, is probably going to vote democrat. That hardly fits your characterization of an endorsement.
Obviously you’re not likely to get dr. Peikoff to answer you, and I don’t think anyone here is able to speak for him, so here’s why I think republicans are more dangerous:
In the 60’s, leftist ideology and government policies peaked in America. There were price-controls, huge amounts of regulation, windfall income taxes all throughout the 70’s, the culture was quickly moving toward the left well into the 70’s.
That ideology however, while it suited the cynical intellectuals, had no answers for the growing masses who fell for it, so many of them turned to the Evangelical Church for guidance. (for a more detailed account of that period check out the video lectures on the ARI page)
My main point is that socialism is indeed a failed ideology, rejected for practical considerations by almost all Americans: in fact, when I talk to any of my non-objectivist friends, the only reason they will all vote democrat (at least for congress) this year, is because they hate the religious right, not because they want more government spending. The reason why the democratic party is weak is in fact their ideology: in a country that didn’t clearly recognize the perils of socialism someone, anyone, running for president against the incumbent republican party, after 8 years of George W. Bush, would be ahead by over 40 % easily. His approval ratings have been under 25% for the past 3 years, and they are much lower than they were two years ago, when the republicans were crushed in the midterms. The only two things holding Obama back this year are his leftist ideology, and to a lesser extent, his history with reverend Wright’s Baptist church.
Anyway, concentrating on Obama is pointless. Even with the huge hype in some of the media, very few people are buying into this cult of personality type coverage: not because Americans are so wise, but simply because he’s not all that charismatic. The crowds of “millions” who show up at his speeches are actually the same few thousand people who show up for Al Gore or are willing to sign a petition to ban dihydrogen monoxide(see funny episode of Penn&Teller’s Bullshit). While I can’t imagine the American people being self-destructive enough to vote for the incumbent party again, Obama will only win by a small margin, according to all the polls, even though a huge republican defeat would make more sense than ever.
So, while people are voting democrat for practical reasons, the only irrational ideology still growing in America today is religion, mainly of the evangelical variety. If you listen to what they preach (or just play close attention to Bill O’Reilly), socialism is definitely part of the package. Now you will ask: But didn’t you say socialism is dead? No, I said it has been rejected out of practical considerations. What has become clear is that the religious right in America is rejecting reason completely, and is sinking into a deeply irrational, medieval frame of mind, in which neither logic, nor practicality are considered. (that is why we have 5000 dead soldiers in Iraq, and is also why Bush has done nothing to curtail the welfare-state or government spending)
What is also clear, is that the Republican Party has become the political wing of the religious right.
If you look into human history, at what caused the fall of the Roman Empire for example, what brought about the Dark Ages, you will understand that the right is in fact the nightmare of anyone who loves reason, science, technology and individual freedom, far beyond Obama’s short-term plans to tax the middle class or even his plans for the healthcare system.