Senator Mark Warner of Virginia became the latest member of the Senate to announce his support for gay marriage Monday afternoon — and perhaps the last to do so with any effectiveness. In the recent history of buzzer-beaters for political benefit, others have not been quite so advantageous on the once hot-button issue.

There's a tricky calculus to figuring out when to hop on a bandwagon. If you're the first to embrace a controversial position, you risk becoming a gadfly. If you're too far ahead of the electorate, you could risk enormous political damage. Wait too long, and you get no political benefit or, worse, look like an opportunist. Or wait way too long, and you can look like you're hopelessly behind the times.

But there's a sweet spot: ahead of the curve among elected officials, slightly ahead of the curve of public opinion, but still with political risk. Time that right, and it's like hitting the jackpot of shameless political opportunity.

As we said, Warner is getting in under the wire. Mother Jones's Timothy Murphy marks the too-late point:

The Supreme Court begins hearing arguments on the issue Tuesday. If the Court voids existing gay marriage laws — or if it looks like it's going to — it's too late to jump on that train. In other words: No more bets, people.

As a lesson for future elected officials, we've put together this handy analysis of how various elected officials did on their timing.

Too early.
There aren't a lot of politicians who jump out too early on controversial issues. Politicians are risk-averse. They're not excited about receiving a lot of critical phone calls. They fear primary races. So it's rare that a politician will actually act early and face the recriminations.

John Kerry in 2004. Perhaps the only politician whose position on gay marriage came too early was Kerry. While he didn't support gay marriage, he did support civil unions for same-sex couples. Kerry was hemmed in politically: a lot of his supporters wanted boldness on the issue, while his opponent's team (read: Karl Rove) worked to put a series of anti-gay-marriage intitiatives on state ballots. All passed. While the role of these initiatives is wildly overstated in that election's outcome, Kerry's support of civil unions certainly didn't provide an easier path forward in close races.

Sweet spot.
Rob Portman. The Ohio senator's announcement last week that he was supporting gay marriage after his son came out was obviously chosen with specific timing. (He's known his son was gay since last year.) By announcing last week, Portman remains ahead of the electorate in that state, but still with a high level of political risk. As the first sitting Republican senator to express his support, he gains an additional level of political benefit. Context matters, and for Portman the context was perfect. His Democratic counterpart, Sherrod Brown, has been openly supportive of gay marriage for some time, opposing various anti-gay-marriage efforts while still in the House. But the standard for a Democrat is different.

How lucky Portman got on timing is just becoming clear. A poll came out Monday showing that more than half of Ohioans support gay marriage. Had Portman announced after the poll came out, he would have looked like an opportunist. The senator almost certainly knew what the numbers looked like last week. The rest of the world didn't.

Barack Obama. Intentionally or not, Obama's announcement of support for gay marriage last spring may end up being one of the most perfectly timed switches on a controversial social issue in recent memory. Before a close presidential election, well ahead of the electorate, seemingly before he was ready — every factor made Obama's decision look like a risk taken for the sake of moral honesty. In November, the president captured three-quarters of the gay vote.

The Democrats who joined Obama after his announcement — Harry Reid, for example — probably hit the sweet spot, too. Demonstrating loyalty to the president at a difficult moment softened the blow

Claire McCaskill. These categorizations are subjective, and a case could be made that McCaskill was just a tad too late. But, again, context matters. And Missouri, the senator's home state, has been slow to embrace the idea of gay marriage. (Last June, only 33 percent of voters supported gay marriage.) McCaskill had the added benefit of being the first senator since Portman to make such an announcement. Two is company.

Too late.
Mark Warner. And three is a crowd. Warner's announcement on his Facebook page came at an odd time: right after McCaskill's roll-out, giving the impression of a guy showing up late to a party. And his home state, Virginia, is a safer state for a Democrat. It went for Obama last year; Missouri went for Romney. Which isn't to say that he garners no benefit from the late move. He just could have gotten more earlier.

Hillary Clinton. As Secretary of State, Clinton couldn't take a public position on political issues. But for a key leader in the party to make an announcement by video in 2013 — as though the act were exceptional — seemed a bit off. Especially since the move followed her husband's announcement.

Behind the times.
Bill Clinton. Before Hillary's video message, the former president announced that he believed the Defense of Marriage Act — one of the issues the Supreme Court is considering and a bill Clinton himself signed into law — was unconstitutional. It was a weird move, by way of an op-ed in the Washington Post, and one that seemed as though it was meant to paper over an unhappy aspect of his well protected legacy. It was almost certainly too late.

Saxby Chambliss. The retiring senator last week didn't embrace gay marriage, but he ensured that his legacy would be carved in stone. "I'm not gay," he said. "So I'm not going to marry one." An unchangeable punctuation mark. No matter how the issue evolves, Chambliss has defined his position on the subject.

There's one last addition to the "Too late" category. Namely: Any other senators that come out in support of gay marriage over the next week. Unless that senator is Marco Rubio. For the third time — context matters.