Significant events are crowding the national calendar for 2012, and each promises considerable drama and suspense for the LGBT community. Here are the 10 most important to watch:

1. The fight for the White House

The difference for LGBT people between having President Barack Obama in the White House and President George W. Bush has been stark. So the consequences of November’s presidential election will also be profound.

Either Obama stays, and things continue to improve, in law and in society’s attitudes, or a new president is elected from a field of Republicans who seem, at times, to be vying for the mantle of most gay hostile candidate.

2. The next decision on Proposition 8

A three-judge panel of the 9th Circuit U.S. Court of Appeals could release its opinions any day now. That’s “opinions,” plural.

Before the panel can rule on the constitutionality of California’s law banning marriage for same-sex couples, it must decide whether the Yes on 8 coalition has legal standing to appeal the federal court ruling that Prop 8 is unconstitutional, and it must decide whether there is any justification for Yes on 8’s request that the lower court decision be vacated.

The list of possible outcomes in Perry v. Brown — the case brought by the American Foundation for Equal Rights with famed attorneys Ted Olson and David Boies leading the charge — is mind-boggling.

Whatever the results, any or all aspects could be appealed to the U.S. Supreme Court immediately or they could be appealed to a full 9th Circuit bench and then to the Supreme Court.

But the panel’s decision will almost certainly have political impact, too. Not only will it affect the momentum of the marriage equality movement, it will almost certainly become fodder in the presidential campaigns.

3. The decision, on appeal, in DOMA

A three-judge panel of the 1st Circuit U.S. Court of Appeals will hear oral arguments, perhaps as early February, in a powerful challenge to the federal Defense of Marriage Act’s denial of federal benefits to same-sex married couples.

The challenge, referred to most often as Gill v. OPM, is actually three consolidated cases, two brought by Gay & Lesbian Advocates & Defenders (GLAD) and one by the state of Massachusetts.

While there are other challenges underway to DOMA, this is the “big guns” challenge and the one most likely to reach the U.S. Supreme Court first. And while there is no deadline by which the panel must render its decision, it is likely to turn out one by year’s end.

Then, as with Proposition 8, the case could go to the full circuit court for appeal or straight to the Supreme Court. And, if the appeals court decision is rendered before the November elections, it will almost certainly provoke debate on the presidential campaign trail.

4.Tammy Baldwin’s historic bid

U.S. Rep. Tammy Baldwin (D-Wisc.) is not the first openly gay person to run for U.S. Senate, but she’s the first who has a real chance of winning. She doesn’t have a challenger for the Democratic nomination to fill the seat being vacated by Democrat Herb Kohl.

But she will have a very tough battle against whomever the Republicans put on the ballot. That’s because the battle will be for more than just one seat in the powerful U.S. Senate, which currently has a breakdown of 53 in the Democratic Caucus and 47 in the Republican. It will be part of a multi-state slugfest between the parties over control of the chamber, the Congress, and the nation’s laws.

5. The fight for the U.S. Senate

Polls at the moment indicate voters are inclined to vote for Democrats over Republicans next November. But that sentiment is not providing a large margin (one or two points), and it’s too soon to guess who the voters will blame for what 11 months from now.

But some Senate races, in addition to Baldwin’s, could have big consequences for LGBT voters. In Virginia, a pro-gay former governor, Tim Kaine, will likely be pitted against an anti-gay former senator, George Allen. In Massachusetts, a pro-gay challenger, Elizabeth Warren, will almost certainly be the Democrat facing incumbent Scott Brown, whose attitude toward the community has been much less friendly. And at least seven other states are expected to have competitive races for the Senate.

6. Counting the ‘gay caucus’

U.S. Rep. Barney Frank (D-Mass.) will start his 40th year in Congress when the House reconvenes Jan. 17. And it will be his last. He announced last year that he would retire.

Without Frank, the clique of four openly gay members of Congress  — Frank, Baldwin, and Reps. Jared Polis (D-Colo.) and David Cicilline (D-R.I.) — will shrink by one. If Baldwin fails to win a Senate seat, it could shrink by half.

But there are prospects for adding members. Openly gay Wisconsin Democratic  Assemblymember Mark Pacon is running for Baldwin’s U.S. House seat. And there are two other openly gay candidates for the U.S. House this November: Marko Liias from Seattle, Wash., and Mark Takano from Riverside, Calif.

So, the number of openly gay members of Congress could go from four to as low as two (though zero is, technically, possible) or as high as six. But no one will have the seniority and clout that Frank has had and used to advance pro-gay measures.

7. On hold, and on defense, in Congress

Pro-LGBT bills, such as efforts to repeal DOMA and pass the Employment Non-Discrimination Act (ENDA), are not likely to see much action in 2012. Anti-gay measures might. Why? Because it’s an election year and Republicans still control the House.

Supportive Democrats will not be inclined to push controversial legislation during an election year, because it can detract from the emphasis on jobs and the economy, where most voters want focus right now. Republicans, on the other hand, have often used hostile measures aimed at gays during election years as a way of putting Democrats on the spot with voters generally and gays specifically.

8. State ballot battles abound

There will be important LGBT-related ballot measures before voters in several states this year. North Carolina and Minnesota will vote on whether to ban same-sex marriage through an amendment to their state constitutions.

Voters in Maine will decide whether to strike down their existing ban on same-sex marriage. LGBT activists in Washington State are gathering signatures to put a measure on that state’s ballot to gain marriage equality.

A small group in California has until May 15 to gather more than 800,000 signatures to put a measure on the ballot there to repeal Proposition 8. And the California Attorney General is expected to announce by Jan. 9 whether opponents of a new bill to include LGBT figures in history as part of the public school curriculum can begin circulating petitions to get a repeal measure on the ballot there.

All of these have the potential to be big, expensive, and consequential battles.

9. Fight for ‘freedom of religion’

The right-wing Alliance Defense Fund and others have a concerted effort underway in the courts to undermine laws prohibiting discrimination based on sexual orientation and gender identity.

Their strategy is to argue that people who discriminate against LGBT people do so because their religious beliefs require them to do so. Their question to the court is, “What rules? The First Amendment guarantee of free exercise of religion or the equal protection clause that says all citizens should be treated equally under the law?”

One case has already reached the U.S. Supreme Court and failed, but other cases — many other cases — are winding their ways through nearly every circuit court in the country. And their outcomes have the potential to chip away at the strength of the nation’s legal mandate that all people be treated equally.

10. Ah, the unpredictable

One of the bigger LGBT stories of 2011 happened in February, and it was one nobody expected: The Obama administration announced it considered the Defense of Marriage Act unconstitutional and would not argue for its defense in most cases.

Given the politically charged atmosphere of a presidential election year, any national  news on LGBT issues is bound to be big.

Top photo: Will Tammy Baldwin become the first openly gay U.S. senator? The Wisconsin congresswoman’s historic bid is just one of the major LGBT stories that will play out in 2012. (courtesy U.S. House)