Is using InTrade illegal?

Vice President Biden is an optimist. And he'd love to put his money where his mouth is, if only it were legal:

Vice President Joe Biden boldly predicted Friday that voters would reject a "Republican tea party" of extreme candidates and Democrats would retain control of Congress this November.

In a pep talk for the party's rank and file, the vice president challenged the widespread notion that significant losses in House races, and perhaps the Senate, could cost the party its comfortable...