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.
Democrats swept the other statewide offices, with Lt. Gov. Kathy Hochul elected on a ticket with Cuomo, and New York City Public Advocate Tish James headed for a win for attorney general against Republican Keith Wofford.
And keeping hold of the Senate is especially important for Trump since it will give the White House the chance to press on with one of his major legacy-building initiatives, restocking the federal judiciary with conservatives.
Early exit polls showed Trump was a major factor for almost two-thirds of voters who cast their ballots, while a CBS News poll found that 55 percent said they disapproved of the president's performance.
But the GOP solidified their Senate majority after an acerbic midterm election that enshrined America's deep political divides and shaped a highly contentious battleground for the stirring 2020 presidential race. Moscow denies meddling and Trump denies any collusion.
Pelosi says that after 2016 Democrats "didn't agonize, we organized".
Trump tweeted late Tuesday, seemingly choosing to focus on the Senate results.
Most Democratic candidates in tight races stayed away from harsh criticism of Trump during the campaign's final stretch, focusing instead on bread-and-butter issues like maintaining insurance protections for people with pre-existing medical conditions and safeguarding the Social Security retirement and Medicare healthcare programs for senior citizens.More news: Congress bound, Minnesota's Ilhan Omar enjoys another first
Speaker Joe Straus, a San Antonio Republican who ousted a fellow Republican with help from House Democrats in 2009, is retiring.
In a statement, Senate Democratic Leader Andrea Stewart Cousins said, "The voters of NY state have spoken and they have elected a clear Democratic majority to the state Senate".
Republicans have picked up three seats in the Senate so far, defeating Democratic incumbents in Indiana, Missouri and North Dakota.
The Democratic gains could have big effects, soon and longer term.
They also held on to competitive seats in Texas, where Senator Ted Cruz fended off Representative Beto O'Rourke, the well-financed liberal darling, and in Tennessee, where Representative Marsha Blackburn prevailed.
It could have been a much bigger night for Democrats, who suffered stinging losses in OH and in Florida, where Trump-backed Republican Ron DeSantis ended Democrat Andrew Gillum's bid to become the state's first African-American governor.More news: Rohit Sharma overtakes Virat Kohli; becomes India`s leading run scorer in T20Is
In south Florida, former Health and Human Services Secretary Donna Shalala defeated Republican Maria Elvira Salazar. Democrat state legislator Laura Kelly will be that state's next governor. Hillary Clinton's 2016 loss to Mr. Trump, coupled with the GOP's ability to retain control of Congress that year, also stunned the Democratic faithful. The president urged supporters to "pretend" he was on the ballot.
With Democrats now poised to take control of the House, Mr. Cummings will likely be in a position as chairman to issue those subpoenas on his own.
Some GOP incumbents remained underwater, including Mark Harmsworth of Mill Creek, who trailed Democrat Jared Mead by about five points.
A record number of women ran for office this election, many of them Democrats turned off by Trump's policy agenda.
If the numbers hold, Democrats would pick up seven seats in the House and two in the Senate. Such a development would divide control of the United States legislature and hinder President Donald Trump's policy agenda for the next two years.
Republicans still had advantages in some areas, giving them hope of retaining a slim majority.
Gillum, the mayor of Tallahassee, was aiming to become the state's first African-American chief executive, and the intense and acrimonious race was marred by charges of racist campaign tactics.
Tuesday night's results are a much-needed win for the Democrats, who have struggled in recent midterm elections.More news: David Haye Exclusive: How to prepare against a fighter like Usyk
Individual races "will be close", she said, but because of the "quality of our candidates" and emphasis on preserving health care, "I feel confident we will win".
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