According to the Cook Report, “Republicans are on track to pick up between four and six seats; it is more likely than not that the number will be at the higher end of — and may exceed — that range.”

The New York Times’s current Senate forecast from The Upshot puts it this way: “According to our statistical election-forecasting machine, it’s a tossup. The Republicans have about a 54 percent chance of gaining a majority.”

Last month, Nate Silver at FiveThirtyEight.com said: “It’s almost certain that Republicans are going to gain seats. The question is whether they’ll net the six pickups necessary to win control of the Senate.” But he continued: “If asked to place a bet at even odds, we’d take a Republican Senate.”

And big-money conservatives are flooding the zone with cash to ensure victory.

Lauren Windsor reported last month in The Nation that Charles and David Koch held their annual summer seminar for “a gang of the world’s richest people,” and, according to a source who attended the conference, “the explicit goal was to raise $500 million to take the Senate in the 2014 midterms and another $500 million ‘to make sure Hillary Clinton is never president.’”

This continues a disturbing trend in which the wealthy tilt right in the fight against the rest. According to a report last month from the Center for Responsive Politics, “So far this cycle, the top 20 deep-pocketed contributors to the joint committees are all giving to conservatives. In contrast, during the 2012 cycle four of the top five donors to [joint fund-raising committees] were giving to Democrats.”