Election and polling analyst Henry Olsen said in an interview that aired Thursday on "What America's Thinking" that the "perfect storm" of factors led to massive gains from Democratic women in the 2018 midterm elections.

"You've got supermajority women, want to elect more women, they're challenging male incumbents," Olsen told Hill.TV's Joe Concha. "It was a perfect storm for Democratic women."

"I think there's two things going on. One is the Democrats were in a challenging position, so that meant that they were taking much freer rein to have new candidates," he said. "Republicans were defending, and that means that the old gender imbalance was still in play."

"The other is that 60 to 65 percent of Democratic primary voters are women," he added. "They're in politics, and they're Democrats because they have female identity at the center of their political agenda."

A record number of women were elected to Congress in the November midterms, with the vast majority being Democrats.

The number of women serving in the 116th Congress is up to 127, from 110 in the last session. Of the 25 women serving in the Senate, 17 are Democrats, while eight are Republicans.

In the House, there are 102 female lawmakers, with 89 Democrats and 13 Republicans.