By Cokie Roberts and Steven V. Roberts

Two words explain the extraordinary significance of the upcoming fall election. The first is “subpoenas.” The second is “women.”

If Republicans lose one or even both houses of Congress, the impact on legislation would be fairly small. President Trump would retain his veto and more than enough support to uphold his rejection of objectionable bills.

Still, a Democratic majority by a single vote in either body would profoundly alter the Capitol. The opposition party would suddenly have the power to chair committees, hold hearings, summon witnesses, hire investigators, pose questions, and — perhaps most threatening to the president — demand to see documents he desperately wants to keep private, like his tax returns and loan arrangements with foreign bankers.

The admission by Trump’s former lawyer, Michael Cohen, that he conspired with the president to pay off two of Trump’s girlfriends, only increases the stakes and the questions.

The word “impeachment” is already being thrown around by some Democrats — a bit recklessly, in fact, since Trump can use that threat to rally his troops in November. But party leaders would be able to deploy many conventional weapons short of that nuclear device.

“Everything gets investigated,” former Republican Congressman Thomas M. Davis III told The Washington Post. “You spend half your time answering subpoenas, digging up documents and having your people appear before these committees. … Frankly, your legacy is ruined at that point.”

“When you give somebody a gavel, they can actually hurt you,” warned Republican strategist Scott Jennings.

“You dream every day what you would do if you were in the majority,” said Rep. Elijah Cummings, ranking Democrat on the House Oversight Committee, to the Post.

Whether those dreams come true depends heavily on women. Democrats have recruited and promoted female candidates in the hope that they provide a graphic contrast to the blustery machismo emanating daily from the White House.

According to the Center for American Women and Politics, 13 Democratic women have won Senate primaries and 154 have been nominated for House seats, including many in the high-visibility races that will decide the majority. In Virginia, for example, women won the Democratic nomination in all four of the most hotly contested districts. Another 10 Democratic women are running for governor.

The gender gap has been a factor in American politics for many years, but it promises to be particularly consequential this cycle. The latest Quinnipiac poll shows Democrats holding a 9-point edge overall when voters are asked which party they want to control Congress. But men favor Republicans by 1 point, 47 to 46; women prefer Democrats by 17 points, 55 to 38.

This vast imbalance recently surfaced in Ohio, where the Republican candidate barely won a special House election in a deep-red district. “The chaos that seems to surround Donald Trump has unnerved a lot of people,” Republican Gov. John Kasich, a frequent Trump critic, told ABC’s “This Week.” “So suburban women in particular here are the ones that are really turned off.”

Not only are these suburban women, many with college degrees, backing Democrats, but their resentment toward Trump is driving them to the polls in huge numbers. The legal troubles of Trump’s lawyer, and his former campaign manager, Paul Manafort, only aggravate the sense of chaos that is activating them politically.

“We’re bleeding among women, and the enthusiasm factor for Democrats is worth 7 or 8 points, and sometimes more,” Republican Sen. Lindsey Graham lamented to The New York Times.

Trump insists that his presence boosts GOP energy, and he plans to campaign widely for party candidates this fall, even telling The Wall Street Journal, “I think the Democrats give up when I turn out.”

All evidence contradicts that fantasy. “He’s enraging the opposition while simply reinforcing a much smaller base,” veteran GOP strategist Karl Rove said on Fox News.

“I’d argue (Trump) could make things worse” for Republicans, said Frank Luntz, another senior party operative, on ABC.

The final outcome remains uncertain. The political website FiveThirtyEight gives Democrats a 3-in-4 chance of winning the House, but that leaves a 1-in-4 chance that they’ll fail. A model used by CBS and YouGov predicts Democrats will likely win 222 House seats — four more than the 218 they need for control. However, their total could drop as low as 211 — seven below the magic number.

But if the Republican nightmare can be summed up in one image, it would be a determined-looking woman with an “I Voted” sticker on her lapel and a subpoena in her hand.

Steve and Cokie Roberts can be contacted at stevecokie@gmail.com.