Sergeant Clifford Stone, in a 2001 conference address, noted fifty-seven alien species that the military had cataloged at that time. He has, in fact, understated the actual number here on our planet, and he neglected (for fear of inciting panic) to discuss the purpose of their presence. It is, in a word, colonization.
Sergeant Stone described the visitors as humanoid and alluded to some of their alien powers, specifically the ability to perceive color in darkness and their general superior sensory acuity. There are other powers even more alarming, including pre-cognition and the ability to effect space-time distortion at the local level. The aliens have developed facsimiles of human bodies and psyches - space suits of a sort - to wear during their stay, but these replicas are imperfect. Those imperfections, both physical and behavioral, are a way that we can identify them. Often, we can also spot them by simply looking at the occupants of earth's most powerful positions.
The Clintons are an interesting case in point. Bill's relationship with his young intern defied logic. Further, his insistence in the face of irrefutable evidence that they never had sex seemed inconceivable to most of us. However, on his home planet, in the distant galaxy of Outragia, that act is not sex at all, but a means of transmitting signals to an orbiting ship by using one's body as an antenna. The Clintons enduring marriage is difficult for many of us to fathom until we recognize that it is not a marriage at all, but a coalition of two alien species. Hillary hails from the planet Pantsuitia, an earth-like planet orbiting a medium-sized star in the near-by Andromeda galaxy. Pantsuitians relish our planet for its proximity and similarity to their own, and for the fashions of the seventies.
The Bush family is another fascinating example of imperfect human imitations. In the case of the young George W, the rulers of his world, Texconnectus, feared that his mental model was deficient to the point of being non-functional, but were surprised to find that those frequent lapses of intellect actually endeared him to the earth's populace. The Texconnectans recognized a need to provide behind-the-scenes support for their emissary, and aligned themselves with the Chenoids. Firm proof of George's alien power was recently displayed in a shoe-hurling incident. A careful review of the video shows that he used precognitive ability and time distortion to dodge the projectiles.
The idea of such powerful beings in our presence with the intent to conquer is frightening and begs the question: Why have they not succeeded? Two obstacles stand between them and earth domination. First, there are but a few of each species. The enormous energy demands of space-time teleportation limits the ability of even the most advanced civilizations to send large occupational forces. They are forced to colonize by wresting control of our institutions and planting their genetic material in the earth inhabitants. Only by such means can they establish their culture on this planet.
The second major obstacle is the competition between the various alien species. They vie with each other for power and control, and have only recently begun to forge alliances like those previously mentioned. This is an alarming development and one which we humans must fight. It is our duty to discourage all non-partisan cooperation and, whenever possible, put the most embarrassing examples of humanity in our highest offices (so that we may be assured of their authenticity). The recent GOP vice-presidential candidate was a grand but unsuccessful effort to do exactly that.