The political tactic of "killing the messenger" does not work in scientific debates. Even if a person has an ulterior motive, their message must be taken at face value, and must be refuted on it's own value or lack thereof.
You don't need to attack Gore to debunk the Global Warming theory, which is still ignoring several important factors:
1. It fails to account for how changes in the sun impact our atmosphere. We have seen a correlation between sunspots and the Earth's temperature. Yet Global Warming theory places carbon dioxide as a more important factor on the Earth's atmosphere than our planet's PRIMARY source of heat?
2. During the period of the dinosaurs, Earth's atmosphere contained larger concentrations of carbon dioxide than it currently does, yet both flora and fauna flourished. If Global Warming is so horrible for the Earth, then how do they account for this?
You don't need to attack Al Gore to find the holes in his message.