Premise:
"By contrast, many nerds can be handsome (Gore) or self-confident to the point of arrogance (Gates, Gingrich)."
Hypothesis: Being smart can give nerds a lot of confidence.

it is not possible to tell

Premise:
"And then there are the Democrats like Ted Kennedy and John Kerry, who have the gall to sign on as co-sponsors of the corporate-welfare bill while holding out for ludicrous federal maritime subsidies."
Hypothesis: The federal maritime subsidy bill complements the corporate-welfare bill.

no

Premise:
"The independent panels, however, say none of the proposed chemical agents are known to cause disease at the low levels which troops faced."
Hypothesis: These proposed chemical agents have been thoroughly tested and proven to not cause diseases in low amounts.
it is not possible to tell