Every off-year campaign has a media script, and this one is labeled “Republican takeover.” It has become an article of faith with so many reporters and pundits that the prospect of House Speaker John Boehner and Senate Majority Leader Mitch McConnell seems almost inevitable.

There’s some evidence for the theory. Democrats are polling badly in many contests — including the Maine governor’s race — and unease has penetrated even to Maine’s two House races. Some polls have previous political unknown Jason Levesque, the Republican, running within 10 points of 2nd District Rep. Mike Michaud, a four-term incumbent. Dean Scontras is in a similar position in his rematch against 1st District Rep. Chellie Pingree, a Democrat facing her first re-election.

But few take the prospect of a Levesque or Scontras victory seriously. Michaud is the classic lunch-bucket Democrat who seems perfectly in tune with his district, which comprises vast stretches of northern and eastern Maine. He once drove a forklift for Great Northern Paper, is fairly conservative on social issues, and has had some legislative successes that benefit his district – such as the Northern Border Regional Commission, designed to bring new federal funding to the St. John Valley.

Pingree is a veteran of four terms in the state Senate and actually did better against U.S. Sen. Susan Collins in 2002 than Congressman Tom Allen did in 2008. She has been diligent in constituent work and is well suited to her southern Maine district.

Maine hasn’t rejected a House incumbent since 1996, when Republican Jim Longley, Jr. was sent home by Allen for hewing too closely to Newt Gingrich’s line.

And if Republicans can’t pick up a seat in Maine, they’re unlikely to make the net gain of 39 necessary to assume control of the House. The Senate, where they’d need to pick up 10 among the 33 races on the ballot this time, looks even less likely.

History is a helpful guide. In the first midterm after a new president takes office, the president’s party usually loses House seats -– as seems virtually certain this year. The only exceptions were in 1934, when Franklin Roosevelt added troops to his New Deal coalition, and 2002, when George W. Bush’s Republicans benefited from the post-9/11 landscape.

But it’s rare to have the political tsunami Republicans would need to recapture either House or Senate, and such shifts are even rarer since the 1970s, when party-line voting dramatically weakened. The exceptions were in 1974, when the Republicans lost 48 House seats to Watergate, and in 1994, when Gingrich won 52 with his clever “Contract with America,” capitalizing on anti-Washington sentiment.

You will have noticed that Republicans are proposing no such contract this year. It’s no secret what has driven Republican poll numbers up and Democratic numbers down. It’s the economy, and particularly persistent unemployment, despite the technical end of the steep recession of 2008-09.

The same forces that helped Barack Obama and the Democrats in 2008 after the collapse of Wall Street are now hurting them as hard times drag on. Yet, Republicans may have made a key error in not proposing any program other than cutting back on spending –- which will make the economy worse –- and trying to repeal Obama’s agenda.

The Contract with America was thin stuff, and its only lasting achievement was a constitutional amendment barring Congress from raising its own pay within the same session. But voters thought they’d be getting things they liked with the contract –- term limits, a balanced budget –- and this nationalized the election while dampening Democratic turnout, which was crucial.

This year, it’s every candidate for him or herself, with such unwelcome events for the GOP as the defeat of Rep. Mike Castle in the Delaware Senate primary, turning what had been considered a sure pick up into a probable loss.

Voters usually punish the party in power when times are bad, but they don’t lose their minds. In the vacuum created by the Republicans’ purely obstructive tactics in Congress, strange plants bloom. Phenomena like the Tea Party, fueled by pure anger and not much else, tend to turn on themselves, and sometimes do so even before Election Day.

America is a land where almost anyone can be elected. Before the last decade, a professional wrestler and an action film hero had never been elected governor anywhere. Before 1980, in fact, a screen actor has never seriously been considered for president. So, a few of the unknowns nominated in this year’s primaries may actually be in Washington come January; but not enough to run the place.