Polls touting a large Republican generic-ballot lead overstate the edge because they screen for likely voters, who skew Republican; YouGov/Polimetrics data confirm independents and Republicans are much more motivated to vote in 2010 than Democrats.

When the Tea Party movement is polled without defining its issues, more people are unsympathetic than sympathetic; but among those who are somewhat sympathetic, the dominant driving issue is taxes and spending rather than social issues.

The likeliest path for confronting unsustainable spending in the U.S. is experimentation at the state level—governors innovating (e.g., Chris Christie in New Jersey, Andrew Cuomo campaigning in New York)—rather than federal action, because the federal government is least able to act and successful state models could spread.

Since the New Deal, U.S. health and social policy has steadily expanded entitlements and coverage (Roosevelt, Kerr-Mills, Medicare/Medicaid, SCHIP, Bush's Medicare drug benefit), and now that nearly everyone is covered, the era of expanding rights gives way to an era of paying bills the government cannot afford—so the eventual solution must look very different, likely removing the employer tax deduction and letting insurance markets vary coverage, or else resembling Britain's system.

The filibuster is not used more often than in the past, but because the parties have become ideologically non-overlapping (bimodal), filibusters are now along strict partisan lines on economic issues—whereas in the mid-20th century the 'conservative coalition' of Northern Republicans and Southern Democrats created cross-party overlap that made the filibuster a less purely partisan tool.

Approval of the health care bill is heavily correlated with personal job status, which helps explain why Nevada (with high unemployment) is one of only two states where 50% approve—so Harry Reid's vote for the bill likely did not hurt him given his state's profile.

Obama will almost certainly win the Democratic nomination in 2012 because a serious primary challenge to the first black president is highly unlikely, even if the economy double-dips; conditions would have to be extraordinarily bad.

The mood of the electorate varies sharply by party: Republicans and Tea Party members are unhappy about government spending, Democrats remain largely satisfied (Obama has ~80% approval among Democrats), but independents—now about 40% and growing—are unhappy about the economy, health care, taxes and spending, and their mood more closely approximates Republicans than Democrats.

Party identification, conceived not as a fixed inherited trait but as a measure that people revise based on events, is a potentially better predictor of the president's party's fortunes than generic-ballot polling, because voters tend not to jump directly from one party to the other but move through 'independent' as a halfway station—so tracking movement toward independent signals trouble for the president's party.

Presidential-election outcomes are far more predictable than congressional ones: a 'guns and butter' model (real income/economic growth plus involvement in foreign wars) predicts whether the incumbent party wins because voters hold the president responsible for the economy and for foreign wars—the model fails mainly in 1952 and 1966.

Republicans went along with financial reform because polls showed about 75% of Americans blamed banks for the crisis and opposed the bank bailouts, creating overwhelming pressure on Republicans not to be seen opposing bank regulation—so a finance bill was politically inevitable.

Hoover's own district-level modeling, which oversamples key swing districts rather than relying on the national average, predicts Democratic House losses of 28 to as many as 50 seats in 2010, meaning Democrats could lose control of the House depending on events before the election.

Presidents enter office with unrealistic expectations that cannot be met, so core supporters fall away (e.g., critics like Krugman and Dowd faulting Obama on the Gulf spill and cap-and-trade, and disappointment over continued Afghanistan involvement), draining enthusiasm from the party and contributing to midterm losses.

The traditional explanation for midterm seat loss—that marginal voters drawn out by presidential-election hype stay home in off years, returning the electorate to its normal party affiliation—broke down around 1988 because Republicans kept winning presidencies while Democrats held the House, so political science lacks a single good explanation for why the president's party loses midterm seats.

Since 1946, the president's party has lost House seats in the first midterm at different average rates depending on party—Democratic presidents lose ~30 seats, Republican presidents ~16—but a major reason for the gap is that Democrats controlled the House for more of that period (a larger sample), so the overall average is roughly 20-23 seats with large variance.

The American electorate can be mapped on two axes—economic liberal-conservative and social conservative-liberal—and tracking the same 1,200-person panel since 2004 shows roughly 7% are economically and socially liberal, ~9% economically and socially conservative, ~24% economically conservative, with the bulk of the public clustered in the middle on both dimensions; these centrist voters decide elections.

In the Senate, Brady forecasts Republicans picking up six to eight seats—not enough for a majority—with North Dakota, Indiana, Delaware and Arkansas likely flipping Republican and about eight toss-up races (e.g., Missouri), so Democrats would lose their filibuster-proof majority.

With the economy unlikely to improve dramatically before November 2010, the Democrats' best electoral strategy is to avoid a national referendum on the economy by casting doubt on what Republicans would do—but blaming Bush no longer works because while Democrats still buy it, independents and Republicans now hold Obama accountable for the economy.

The current period is structurally unusual: in normal partisan realignments when one party gains the other loses, but in this cycle both Democrats and Republicans have lost share while independents have risen—Republicans declined from about 2005, Democrats then fell without Republicans regaining, an asymmetry rarely seen in data going back to 1937.

Standard congressional forecasting regressions over all 435 seats are misleading because gerrymandering and incumbency fix the outcome of roughly 360 seats, leaving only about 60-70 genuine swing districts; the meaningful action is therefore in those swing districts, not the averaged national model.