Shorter conservative movement: we believe the apparently benign Obama administration is a secretly totalitarian, figuratively alien (unAmerican) entity, with nefarious plans to destroy America; therefore, a tv show about an apparently benign but secretly totalitarian, literally alien entity, with nefarious plans to destroy the planet is obviously about the Obama administration.
It's just a syllogism of conservative illogic for movement conservatives. Likewise, they believe that President Obama is a Nazi, a "liberal fascist"; therefore a remake of an allegory about Nazis is also obviously about President Obama.
And since one single journalist is pressured by the Visitor leader into giving her a soft ball interview, the show is also obviously taking on "Obama-mania."* That there is such a thing as Obama-mania in the first place is simply an article of faith for movement conservatives: the press is always "liberally biased" for liberals against conservatives. This is an axiomatic truth that can not be effected by reality (also see here.)
*In the original 1983 series, the analogous journalist character becomes the Visitor leader's press secretary. In the new series, the journalist is actually more skeptical of the leader's motives than the original character was. One could just as easily interpret the character having been pressured into reporting favorably on the Visitors to something like Dan Rather saying after 9/11, "George Bush is the president. He makes the decisions, and, you know, it's just one American, wherever he wants me to line up, just tell me where. And he'll make the call." I don't believe the creators had that in mind, but it goes along way towards demonstrating how singular the worldview of Beck and Hannity and the rest is.
Update: From Media Matters
Fox News' Sean Hannity, Bill O'Reilly, and Glenn Beck have all endorsed the new ABC television show V, citing the show's depiction of aliens seeking to conquer Earth who offer to provide universal health care as a critique of "Obama-mania" and "Obamacare." This is not the first time Fox News personalities have promoted a television show to buttress their right-wing world view; many of them cited Fox's 24 to defend the use of torture by U.S. authorities, among other conservative positions.