Sleep well, wear comfortable shoes and bring lots of snacks. That’s the advice floating around the north end of the U.S. Capitol as the Senate prepares to embark on one of its most unique, byzantine — and useless, depending on whom you ask — traditions.

The ritual of “vote-a-rama” (yes, that’s an official term) is what stands between Republican senators and their goal of  passing a tax overhaul by Christmas. It’s expected to begin soon.

Senators must endure dozens of policy amendments in rapid-fire succession stretching late into the night, a marathon procedure former New Hampshire Sen. Judd Gregg once described as "the Senate's equivalent to Chinese water torture."

Only after the Democrats tire themselves out do Republican leaders get the opportunity to tee up a final vote.

Why endure upwards of 12 hours of legislative abuse?

Republicans chose this route because it allows them to bypass a Democratic filibuster, the traditional tool for delaying or blocking votes.

With 52 senators, the GOP is eight votes shy of a filibuster-proof majority. That leaves the party with the option of working with Democrats on legislation, or work around them using special budget legislation that requires only 50 senators to pass.

Republicans chose the latter.

Part of the deal with that special budget legislation, however, is that they must partake in a vote-a-rama.

Senators typically vote late into the night on alternating Democratic and Republican amendments, with little more than a minute or two of debate on each. It’s a radical departure from the chamber’s typically slow and dull approach , where party leaders will go to great lengths to protect their lawmakers from tough votes.

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The scene it produces on the Senate floor is as fascinating as it is mundane. Senators sit at their desks, a rare sight, reading newspapers and magazines, chewing on candy from the chamber's designated sweets drawer and thumbing their smartphones as their colleagues give short speeches or cast votes. Often there is takeout delivered to the chamber's back rooms, which commonly blast out the evening's professional sporting event of choice.

“It’s not a very pleasant experience,” said U.S. Sen. Johnny Isakson, R-Ga., “For a while you enjoy it, and then all of a sudden after six or seven hours you realize what a waste of time it is.”

The amendments senators vote on won’t carry the force of law even if they’re adopted. What they do is offer a messaging opportunity, particularly for Democrats.

As members of the minority party, Democrats don’t have control of the Senate floor and hence have little opportunity to go on the offensive when it comes to their policy agenda. Vote-a-rama offers that opportunity, and a chance to force colleagues to vote on tough, sometimes embarrassing issues that could come back to haunt them later on the campaign trail.

Democrats perennially tee up votes on climate change and instituting a carbon tax, issues that are popular with their base but often make Republicans squirm. It’s also common to see amendments that force senators to vote against issues they support more broadly due to technicalities or other details.

Georgia Republican David Perdue wants to eliminate the vote-a-rama process as part of a larger budget overhaul effort.

“You pay attention because you never know when somebody slips in a real vote,” he said. “If I do one thing in my time up here, it’s to change this budget process.”