Because when one week Hillary Clinton is talking about a gas tax holiday and the next week she's talking about suing OPEC at the WTO for being a monopoly...
She's either confused, misinformed, or pandering. After all Russia has the second largest oil reserves of any nation in the world, Venezuela's oil reserves aren't anything to sneeze at, and America produces a considerable amount of oil in its own right. Given those facts how can OPEC have a monopoly? I'm willing to bet that if she pursued such a course of action a few members of OPEC would begin performing "refinery maintenance" resulting in diminished supply just in time to rain on her gas tax holiday parade.
"We’re going to go right at OPEC," she said. "They can no longer be a cartel, a monopoly that get together once every couple of months in some conference room in some plush place in the world, they decide how much oil they’re going to produce and what price they’re going to put it at," she told a crowd at a firehouse in Merrillville, IN.
"That’s not a market. That’s a monopoly," she said, saying she'd use anti-trust law and the World Trade Organization to take on OPEC.
She's either confused about the definition of monopoly, not listening to the experts again, or pandering. Given the fact that she is a lawyer I'm pretty sure she knows what a monopoly is and given her intelligence, her education, and the nature of her job I highly doubt that she's quite that ill informed. So that seems to leave only one possibility.