Yes, yes, we’ve all heard the “all-politics-is-local” bromide with regard to off-year elections.

While it is no longer an operative, let alone true, statement – as the nationalized election cycles of the Bush years so clearly confirmed — there is one certainty with regard to the pop punditry of former House Speaker Tip O’Neill: Winning players and parties never use it, while losers invariably rely on it.

O’Neill, himself, never took the local line all that seriously when Democrats were doing well. Famously, he hailed the off-year election results of 1981 (Democrats won the Virginia governorship and lots of mayoralties) as a signal that his party was coming back from the battering it had taken a year earlier at the hands of Ronald Reagan’s Republicans.

So don’t buy the “analysis” that says that the odd assemblage of local, state and national elections that will be held tonight will offer little or nothing in the way of insight regarding the political zeitgeist.

In fact, we will get indications tonight about the strength of Barack Obama’s presidency and the Democratic Party, about the collapse or resurgence of the Republican Party, about “Tea Party” pressure, independent politics and social policy. This is the 2009 election, not the 2010 election, and much can change in a year. But signals sent tonight will shape decisions and strategies with regard to next year’s House and Senate races.

The only question has to do with how clear the signals will be.

Here are four scenarios for considering the results:

SCENARIO ONE: “HAPPY DAYS ARE HERE AGAIN”

Democratic Governor Jon Corzine is reelected in New Jersey and, against all odds, Democrat Creigh Deeds hold the open Virginia gubernatorial chair for his party.

Moderate Democrat Bill Owens wins the special-election to fill a historically Republican U.S. House seat in upstate New York and progressive John Garamendi holds a Democratic seat in a California special.

Maine voters make their state the first to back same-sex marriage in a referendum and Washington state voters preserve civil union protections (“same-sex registered domestic partnership”).

New York Mayor Mike Bloomberg, running as a moderately progressive independent, is narrowly reelected over Democrat Bill Thompson and Democrats closely ties to the Working Families Party sweep other citywide posts. Seattle’s Mike McGinn wins, as do other progressives in municipal contests around the country.

Bottom-line: Even if Democrats lose one of the big-four races (Virginia governorship), they’ve got more than bragging rights. President Obama, on the one year anniversary of his election, will be able to say that his coalition remains strong and that the opposition — for all the noise it has made — is dysfunctional. He’s got more room to move, and Democratic leaders in the House and Senate can say to reluctant members: “Now, let’s talk about that public option…”

SCENARIO TWO: “WATERLOO”

Forget about the health-care fight being Obama’s Waterloo — as loathsome South Carolina Senator Jim DeMint famously predicted. The Obama presidency is dealt a brutal blow as voters who a year ago said “yes, we can” now say to the president: “No, you can’t!”

Democrats lose the New Jersey and Virginia governorships and the special election in New York’s 23rd district. If Garamendi wins in California, it won’t be noticed by the east-coast obsessed pundits (California results come late) and November 3 will be declared the day of Republican resurgence.

Bloomberg’s New York win will be spun as a sort-of Republican victory, even though he ran on an anti-gun, pro-gay, big government platform, and if Atlanta independent Mary Norwood wins that city’s open mayoral seat the result will also be painted as good news for Republicans (even though Norwood finished her campaign with adds promising that she wasn’t a closet Republican and recounting her votes Barack Obama, John Kerry, Al Gore, Bill Clinton and, uh, Ross Perot).

If gay rights gets beat in Maine and Washington state, the line will be that it is not just the GOP but a deepening conservatism that is sweeping the country. That sentiment will coalesce with “Tea Party” celebrations of the win by Conservative Party candidate Bill Hoffman (formerly opposed by the national GOP but finally embraced) in the New York special, as the far right suggests it is time to disinvite all remaining moderates from the Grand Old Party.

It won’t just be Limbaugh, Beck, Hannity and the Foxists spinning this scenario. The analysis that says Obama has been dealt a serious blow will be broadly voiced. And it will be heard loudest and clearest in Democratic circles, where moderate Democrats in the House and Senate will begin to put even more distance between themselves and the White House. The cause of meaningful health-care reform — and, probably, banking reform — will be dealt a serious setback.

SCENARIO THREE: “STUCK IN THE MIDDLE WITH YOU”

Mixed results let everyone claim victory.

Corzine coasts to victory in New Jersey, but Deeds is decimated in Virginia. New York 23 goes to Conservative Hoffman, but California 10 goes to liberal Democrat Garamendi.

Mayoral results are mixed and referendums send signals in different directions.

The spin here has less to do with Obama — who will be able to claim a sort of victory in New Jersey, where he campaigned hard for Corzine — than with the Republican Party. The resurgent right will claim that New Jersey was lost because GOP nominee Chris Christie was too moderate. And they will make a big deal about the fact that hard-right conservative Republicans won top jobs in Virginia, a state that voted for Obama in 2008.

This is actually the worst result for establishment Republicans in Washington. They would be better off with a big Democratic night, which would allow them to argue that moderation is still called for.

SCENARIO FOUR: “INDEPENDENCE DAY.”

Independent Mike Bloomberg wins huge in New York. Independent Mary Norwood is elected mayor of Atlanta — the first white candidate to win the job since 1969.

New Jersey Independent Chris Daggett, an “underdog and underfunded” candidate who won key endorsements and captured the imagination of a lot of suburban voters, runs unexpectedly well. He does not win, but he gets a high percentage (above 15 percent) and can clearly be seen as having influenced the result — probably for Corzine.

New York Conservative Bill Hoffman wins on a third-party line, even though he had broad (if somewhat grudging) GOP support at the end.

The Working Families Party flexes its muscles in New York City, winning unexpectedly high votes for its candidates on its line. And the WFP shows strength in Connecticut, where it is also operating.

Some supposedly solid mayors — say Boston’s Tom Menino — get beat and the general message of the day (directed at the two mayor parties) is “a pox on both their houses.”

This is a result that will frustrate the party pundits, but it could be the most meaningful one as regards the 2010 state and federal elections, as it might suggest that Americans who were once just frustrated with the GOP are now frustrated with Obama, too. This opens up the prospect for a freelance and freewheeling politics that could at least briefly shake the foundations of both parties, as was seen in the 1990 and 1992 where figures as diverse as Paul Wellstone, Bernie Sanders, Ross Perot and David Duke became serious competitors.

From a small “d” democracy standpoint, this could be an energizing result. But it is also an unstable result, which will have Democratic and Republican insiders scrambling to look like insurgents. Translation: Lots more talk, lots less action, in Washington.