Jacob Hacker and Paul Pierson have an interesting op-ed comparing the fall election to the 1982 election. In 1982, Republicans had a huge financial advantage, largely because Democrats spent most of their money on lopsided races for unchallenged incumbents. (Will Rogers strikes again.) This year, the Democrats so have a financial advantage, but it's probably swamped by outside pro-Republican business money:

Unlike the Democrats in 1982, Republicans have a large assortment of business lobbies and ideological activist groups doling out dollars to defeat vulnerable opponents, in addition to what the party is spending.

The 800-pound gorilla is the U.S. Chamber of Commerce, which has emerged as the deepest-pocketed foe of the Obama administration. It has pledged more than $75 million to defeat high-profile Democrats. That’s more than the combined total of the $22 million cash on hand of the RNC and $36 million of the Democratic National Committee. With its huge resources and ability to target money on critical races, the Chamber’s expanding role is almost like giving the Republicans an extra national organization.

Other resourceful interest groups dissatisfied with the Obama agenda are piling on. Financial industry players, once strongly supportive of Democrats, are donating twice as much to Republican Senate candidates as they are to Democrats. Health insurers, once favoring Republicans 2-to-1, now are backing them by 8-to-1.

The details about health insurers and finance is interesting. Those industries, especially insurers, were willing to support Democrats when Democrats controlled the government and were writing important legislation effecting them. This gave the impression that insurers wrote health care reform for their benefit. In fact, they were protecting themselves against downside risk. And their overwhelming support for a party pledging to overturn the Affordable Care Act shows that they hardly see it as a subsidy.