The mayor and congressional delegate may top the ballot in Washington, D.C.'s primary on Tuesday, but the real drama for voters has to do with waiters, waitresses, bartenders and busboys.

Incumbent Mayor Muriel Bowser is expected to glide through to the nomination with no significant opposition, and the majority of incumbents on the D.C. Council are predicted to secure the Democratic nomination. The same goes for Eleanor Holmes Norton, Washington's long-serving non-voting delegate to the House of Representatives.

The actual election in November is even more of a formality in the District of Columbia, where the Republican Party holds little sway.

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The greatest question mark surrounds a divisive ballot initiative that would change the way that restaurants and bars pay their tipped employees. Initiative 77 would eliminate the "tipped minimum wage" — the two-tiered system under which restaurant and bar owners pay servers, bartenders and bussers a lower hourly wage with the expectation that they will be compensated with tips from customers.

Currently, these employees can make as little as $3.33 per hour; however, the employer is legally required to make up the difference if the employee's salary plus tips add up to less than the current minimum wage of $12.50 per hour.

The ballot initiative would require employers to pay everyone at least the minimum wage and would incrementally raise that minimum wage up to $15 per hour by 2025. A similar policy was adopted in New York City in 2015.

Proponents of the initiative argue that it would protect employees from unscrupulous owners who refuse to follow the law and match wages to bring earnings up to $12.50 per hour. They also say it would reduce sexual harassment by making servers less dependent on the whims of sometimes-inappropriate customers.

However, the proposal has been opposed by a large percentage of both owners and tipped employees. Owners claim that the financial hit could force many bars and restaurants to close — and those that stay in business would only do so by introducing a new service charge, which would have the effect of eliminating most tipping.

Many servers and bartenders also say they are already guaranteed at least the minimum wage under the current law while retaining the potential to earn far more depending on those tips.

The controversy has played out publicly in the many bars and restaurants of Washington, with signs on the walls and many waiters, waitresses and bartenders wearing pins encouraging citizens to vote "no." While those who oppose the initiative have been particularly vocal in the weeks leading up to the vote, observers say it's difficult to predict exactly how the vote will go.