WASHINGTON (Reuters) - They voted to “drain the swamp” in Washington, D.C., but on the night before Donald Trump was sworn in as the 45th president of the United States, they came to wallow in it. At parties across the city, Trump supporters danced and drank to celebrate an incoming president that they said would shake up a city that they saw as corrupt, complacent and out of touch with the rest of America. “Washington is freaked out. They’re about to lose power,” said John Workman, a former mayor of Palm Beach Shores, Florida, as a pair of costumed robots danced to “Sweet Home Alabama.” Ironically, Workman and other Trump supporters were participating in a Washington ritual as old as the city itself - the crush of balls, parties and protests that mark the inauguration of a new U.S. president. Trump takes office after a bitter presidential campaign marked by allegations of sexual harassment, race baiting and foreign hacking, and some of the parties were apparently as divisive as the president-elect himself. Outside the DeploraBall, a gathering of tech-savvy Trump backers who take pride in offending liberals, several hundred protesters shouted obscenities as they squared off with riot police on the streets.  Police deployed chemical spray after protesters threw trash at those leaving the building, according to the Washington Post. Elsewhere in the city, Trump backers wearing American flag-themed apparel and red “Make America Great Again” hats shared sidewalks with people carrying signs that called the incoming president a fascist.  Helicopters roared overhead as a pickup truck towing a “Honk 4 Trump” trailer blared the 1971 Don MacLean hit “American Pie.” Trump himself has struggled to attract top-level talent for the festivities, settling on lesser known acts like Three Doors Down for a concert at the Lincoln Memorial earlier in the day. He wasn’t the only one with problems. The Garden State party had to scramble for entertainment after a Bruce Springsteen tribute band canceled on the New Jersey-themed event, saying the artist whose songs they played would not approve. That didn’t seem to phase Trump, who made an appearance at a candlelight dinner for donors in Union Station, promising “four incredible years” and bragging about his surprise November victory.  “I think I outworked anybody who ever ran for office,” he said. Across town, the New York Society ball could boast rare bipartisan bona fides as the home state of both Trump and his Democratic rival, Hillary Clinton. “If Hillary had won, all this would still happen,” said Brenda Alford, 59, who was dressed in a gold skirt and a gold silk top as a tribute to Trump’s gilded Manhattan residence. A Trump supporter, she bought tickets before the Nov. 8 election. Held at the Fairmont Hotel, which recently completed a $27 million renovation, the party featured a giant Teddy Roosevelt mascot, celebrity host Joe Piscopo, and political figures from both parties. Several Republicans at the ball confided that they were not in town to celebrate Trump’s victory as much as they were to celebrate the end of Democratic President Barack Obama’s term, and, above all, have a good time.   To some partygoers, the soiree lacked a certain energy.  “If Trump were here he would be disappointed with the lack of ladies on the dance floor,” said James Koutoulas, a tuxedo-clad hedge fund owner from Florida, as he nursed a vodka tonic. Indeed, the dance floor was largely free of dancers, female or otherwise, until the band struck up a version of Neil Diamond’s “Sweet Caroline.”  As the party picked up, Koutoulas mused about how Trump’s freewheeling style might affect his profits as a hedge fund manager.     “I’m a CEO. Everyone is terrified of what a Trump tweet could do to their bottom line,” he said.  “The terror is being used for good — so far.” 