Every year it's one of the most fraught decisions in Washington: How to respond to the State of the Union?

For half a century, the out-of-power party has tried to capi­tal­ize on the dregs of audience left over from the president's ratings bonanza of a speech by mounting its own aftershow — the same way "Talking Dead" or "Watch What Happens Live" hope to capture fans of zombies and real housewives.

So naturally, the opposition party feels pressure to find a speaker who can do it all. Can the speaker address a key subset of voters without appearing to pander? Offer a singular vision for an often fractured party? Rally the base while also expanding the tent?

This year, Democrats tapped an Irish American millennial who speaks Spanish to give a speech from his deeply liberal congressional district in Massachusetts. From an auto-body shop in a struggling mill town. His name is Joe Kennedy. (Yes, he's also a Kennedy.)

"I'm just hoping I can make it on and off the stage without tripping, dehydrating or ruining my career," he said in a statement to The Washington Post.

Kennedy knows his history. He's aware that even a candidate who checks all the boxes could end up with a speech that's basically a bust. It usually is.

"It's a very hard job to be successful in," said Republican consultant Alex Conant. "You're following the president who has the best theater, the best visuals, and live audience. Then you cut from that to a direct-to-camera speech that often looks like a hostage video."

Conant would know. In 2013 he worked for Sen. Marco Rubio, who as a "rising star" Republican from Florida had been given the opportunity to respond to President Barack Obama's State of the Union. Rubio had prepared what Conant considered an excellent speech laying out his bright vision for the GOP. Perhaps people would still remember it today, if the room hadn't been so hot.

Instead, a sweaty and dehydrated Rubio licked his lips and lunged nearly out of the frame to grab a small, poorly placed water bottle for a quick swig. This is the only image still with us today.

Maybe we're shallow for focusing on a visual miscue like that. But then again, it was hilarious. And it's because of dumb, unavoidable things such as the water bottle incident that the response is often called the "worst job in politics." Remember when then-Gov. Tim Kaine's relentlessly wry left eyebrow practically climbed off the top of his forehead and escaped into the Virginia night? Remember when Louisiana Gov. Bobby Jindal shuffled forward like a nervous valedictorian to give a stiff, singsongy address? Remember when Democratic Gov. Steve Beshear sat in a Kentucky diner last year, and all those "blue collar" "working class" folks behind him didn't know whether to look at the camera or not?

Either you remember these things, or you remember nothing at all, because you almost certainly don't remember what any of these people said.

And yet, for all its vaunted reputation for being one of the worst jobs in politics, this speech isn't necessarily a career-killer. Jindal probably didn't lose his chance to become president because he came across like Mr. Rogers in his State of the Union response. He probably lost his chance to be president because he came across like Mr. Rogers in general.

And Rubio may still get razzed for being one of the thirstiest politicians in America, but it hasn't dampened his prospects.

"We ended up making a ton of money selling water bottles," Conant said. "People just always remember something if it's unusual."

It's been fashionable to complain about the demands of the job ever since the first SOTU response in 1966.

"Each of us will have about 14 minutes to discuss the State of the Union," Sen. Everett Dirksen (R-Ill.) said in a television appearance along with then-Rep. Gerald Ford (R-Mich.) after one of President Lyndon B. Johnson's SOTUs. "That is a short time for a gigantic task."

The reviews, though, were good.

"The GOP voice may not be more widely heeded in Congress," The Washington Post wrote at the time, "but it is being more widely heard in the country."

Over the years, the opposition parties kept trying to find ways to keep their responses fresh and interesting to an audience close to losing it after having their ear bent by the president for an hour or more. In 1970, the Democrats tapped seven lawmakers to do the talking; in 1972, the panel took unscripted calls from the public. In 1985 young Gov. Bill Clinton recorded what looked like an infomercial, a move so cringeworthy they never did it again.

This year, the event for Democrats feels especially existential. They are mired in the minority in both the House and the Senate. There is no clear leader of the party and no clear message for how to move forward.

"This is the time for them to preview what they stand for," said Republican strategist Doug Heye. "They can energize their base. And I think they were smart to go with Kennedy. He has serious substance. He can speak about more than just 'resisting' the president."

Kennedy, despite his famous last name, has kept a relatively low profile during his three terms in the House but is widely considered a future leader of the party. Equally important, he also has not expressed imminent interest in running for president. House Minority Leader Nancy Pelosi (D-Calif.), who had the responsibility of organizing this year's response, is said to have wanted to avoid picking a senator with designs on a 2020 campaign for the White House, and all the complicated politics that would entail.

Last year, Democrats picked a 72-year-old governor from a red state, in part to remind rural and centrist voters that they hadn't forgotten about them. This year, they wanted to remind people they actually do have some young guys, too.

"Joe Kennedy agreeing to lead the response to the president is so important because when he speaks people listen," Pelosi said.

But will they remember?

"No matter how well a response goes, it will be overshadowed by the State of the Union speech itself," Heye said. "And if not . . . no doubt Trump's Twitter feed will change the conversation by the next day."