Among those expected were Trump's adult children, White House aides, Republican officials and presidential friends. The Republicans had an advantage in Senate races because elections were held for only 35 seats in the 100-member chamber and many of them were in states that often lean Republican. Democrats blamed the charged political atmosphere for the increase in anti-Semitism.
Republican Mike Braun opened an early lead in the crucial Senate showdown in IN with incumbent Democrat Joe Donnelly, but the race was too close to call with just 20 per cent of the votes in.
Aides set up televisions in the White House residence for Trump, first lady Melania Trump and their guests to watch election results come in, with the sets tuned to different cable news channels. The GOP's grip on high-profile governorships in Georgia and Wisconsin were at risk as well.
After a divisive campaign marked by fierce clashes over race, immigration and other cultural issues, Americans voted on Tuesday to determine the balance of power in the US Congress and shape the future of Donald Trump's presidency.
Strong turnout is reported across the nation, in particular among young voters.
Fernando Rivera, a 53-year-old small-business owner in Miami, said he voted for all Republicans because he wants Congress to support Trump and his economic policies. Only 4 in 10 said the country was headed in the right direction, while almost 6 in 10 viewed the country as off on the wrong track. About 15 percent said that this was the first time they'd voted in a midterm, according to CNN, compared to about 10 percent who said they were first-time voters in the 2016 election.
US President Donald Trump arrives for a "Make America Great Again" campaign rally at McKenzie Arena, in Chattanooga, Tennessee, on November 4, 2018.
But two years after an election that proved polls and prognosticators wrong, an air of uncertainty - and stormy weather across parts of the country - clouded the outcome of high-stakes elections from Florida to Alaska and everywhere in between.
Democrats would need all five of those races to go their way presuming they hold the seats they're expected to, plus pick up a seat in a longshot like Texas or Tennessee or MS to claim a majority. Montana Sen. Jon Tester faced the toughest battle of that group, while moderate Joe Manchin, a former governor and brand name in West Virginia, was increasingly seen as safe in a state Trump took by 42 percentage points.
In gubernatorial races, Republican Kris Kobach, a Trump ally, was beaten by a Democrat in Kansas. What was not normal was that Menendez had been indicted on corruption charges and escaped with hung jury. In both Senate and House races, Democrats have focused heavily on health care and protecting people with pre-existing medical conditions.
About a half-hour later, he gave GOP Rep. Peter King a shout-out.
Trump pointed to his boisterous rally crowds as proof that Republicans were surging at the right time, rejecting suggestions that Democrats entered Election Day with an edge in enthusiasm. Shalala will replace retiring Republican Ileana Ros-Lehtinen.
The Associated Press called the very first US House race at 6:32pm, when Republican Hal Rogers safely won re-election in Kentucky's fifth congressional district.
But with his party losing its majority in the House, the results represented a bitter setback for Trump after a campaign that became a referendum on his leadership.
The Senate story this cycle has centered on the favorable map for Republicans with 10 Democratic incumbents running in states Trump won in 2016 - five of them by double digits. Potential 2020 Democratic presidential hopefuls who seemed certain to win included Vermont independent Bernie Sanders and New York's Kirsten Gillibrand.
Political gridlock between the White House and Congress could hinder Trump's pro-business agenda and raise concerns about USA political instability, but investors may have already priced this in. Among those expected: Vice President Mike Pence and former House Speaker Newt Gingrich, an informal adviser to the president.
If Democrats capture the House, they could block Mr Trump's agenda and launch congressional investigations into aspects of Mr Trump's administration, from his tax returns to possible business conflicts of interest and the nature of his 2016 campaign's ties to Russian Federation.
Voters are ecstatic about the quantifiable results they have experienced under the Trump administration and they are eager to experience even more positive results and to see promises continued to be kept, which they recognize will be much harder for the president to do with a House or Senate controlled by the Democrats. Perhaps more important, they would claim subpoena power to investigate Trump's personal and professional shortcomings.