Republican women beat incumbent Democrats for five House of Representatives seats in the Nov. 3 election.
Businesswoman Nancy Mace, 42, unseated first-term Rep. Joe Cunningham (D-S.C.), 38, in South Carolina's 1st Congressional District.
State Sen. Stephanie Bice, 46, emerged victorious against first-term Rep. Kendra Horn (D-Okla.), 44, in Oklahoma's 5th Congressional District.
Yvette Herrell, 56, a businesswoman, won in a race against Rep. Xochitl Torres Small (D-N.M.), 35, who represented New Mexico's 2nd District.
And Michelle Fischbach, the 55-year-old former Minnesota Senate president, triumphed over longtime Rep. Collin Peterson (D-Minn.), 76, in the state's 7th Congressional District.
All received endorsements from President Donald Trump.
As of 5:30 a.m. on Wednesday, according to Decision Desk, Democrats had secured 182 House seats, compared to 176 for Republicans.
A party needs 218 seats for a majority of the lower congressional chamber.
Democrats held a significant advantage in the House in the 116th Congress, starting the term with 235 seats to the GOP's 199.
Only 15 Republicans were women in that Congress.
Fischbach said in an early morning statement that she was honored to receive support from Minnesota families.
"I am grateful for the backing and am excited to hit the ground running in Washington to work on behalf of MN," she said.
Tom Emmer, chairman of the National Republican Congressional Committee, said Fischbach would be "a true conservative voice in Congress."
Salazar thanked voters for their support. She had painted Shalala as a socialist and said she was against socialism.
"As a first-generation Cuban-American whose parents fled socialism, Maria is a force to be reckoned with and will always stand up for freedom, not socialism," Emmer said in a statement.
Bice said in a statement that she was "incredibly proud and honored to be elected." Emmer praised her as a "tireless advocate for Oklahoma taxpayers."
Mace posted a photograph on Twitter showing her smiling after the election was called early Wednesday.
"We did it!!" she wrote.
"Congratulations to Nancy Mace on her victory. As the first female graduate of the Citadel and now the first Republican Congresswoman for South Carolina, she is a barrier breaker who will continue to fight for South Carolinians and the Lowcountry," Emmer said.
Herrell said in a statement: "It’s the honor of my life to be elected to serve #NM02. My commitment to each citizen of our district is that I will serve each of them with integrity as we work together to rebuild our economy and protect the values that make America great!"
None of the Democrats appeared to have conceded as of early Nov. 4.
Democrat Kathy Manning, meanwhile, flipped a seat held by Republicans in North Carolina.
Manning, 64, a lawyer, beat GOP nominee Lee Haywood for the seat that was held by retiring Rep. Mark Walker (R-N.C.).
Black Lives Matter activist Cori Bush, another Democrat, emerged victorious in the race for Missouri's 1st District. Bush, 44, beat incumbent Rep. William Lacy Clay, 64, in the Democratic primary earlier this year.