OPINION — Democrats have four qualified, tough, smart, female senators running for president. And that might be a problem, because they just tried that against Donald Trump and it didn’t work in 2016.

It’s not that Sens. Kamala Harris, Elizabeth Warren, Amy Klobuchar and Kirsten Gillibrand wouldn’t each make an excellent president. Like Hillary Clinton, it’s clear that they have all put a great deal of thought into how they’ll run and how they would lead.

They’ve done the hard work of designing policy-specific platforms; they’ve built their early organizations; and all four have put together travel-heavy, strategic early-state rollouts. So far, they have come off as professional, earnest and conventional — in other words, so similar to Clinton that it’s hard to see why the results of their campaigns against Trump would be any different than hers was.

I’ll add right now that it’s completely unfair to compare the female candidates only to one another, and equally unfair to compare them to Clinton, as if simply being a woman puts them all in one campaign lane and male candidates in another.

But consider what voters know about each of them from their very first presidential introductions — four women, all Democrats, all senators, all lawyers, and all promising to address income inequality, the cost of health care, climate change, and the country’s broken campaign finance system. Likewise, Clinton, a female Democratic senator, championed all of those issues too.

And go back to this scene: A female senator with Midwestern roots stands in front of an adoring crowd and announces she’s running for president. A river in the background makes for a beautiful backdrop, while the island where she stands tells the all-American story of immigrants, opportunity and the dignity of hard work. Was it Amy Klobuchar on Boom Island, Minnesota, this weekend or Hillary Clinton on Roosevelt Island in 2015? Both, actually — though Klobuchar’s announcement this weekend had the added twist of happening in a whiteout Minnesota blizzard.

Also watch: Amy Klobuchar is running for president — Here are some congressional basics

Nothing new

Let’s try another one: The female senator from New York announces her presidential bid, promising to fight for America’s children as hard as she fights for her own family. She promises to bring Republicans and Democrats together to get things done, especially on the cost of health care and the existential crisis of climate change. Was it Kirsten Gillibrand on “The Late Show” with Stephen Colbert? Yes. And Hillary Clinton in her own 2015 kickoff.

Or what about this? A female senator, seasoned and tough, lays out the fight she’s ready to take on for the middle class as she announces she’ll run for president. “Americans have fought their way back from tough economic times, but the deck is stacked against them,” she says, promising “an economy that works for everyone.” That was Hillary Clinton in 2015, who was followed almost word-for-word this weekend by Sen. Elizabeth Warren in Lawrence, Massachusetts. “This is the fight of our lives, to build an America that works for everyone,” Warren declared.

But what about Kamala Harris? The daughter of a Jamaican father and Indian mother declared her run in Oakland, California, last month to a large, diverse crowd, where she described her work as a lawyer and prosecutor. She explained that from her first courtroom appearance, she’s always presented herself as “Kamala Harris, for the people,” which happens to have become her super-sharp campaign slogan.

“No one should be left to fight alone,” Harris said, adding later that it was her mother who shared her fighting spirit. Not for nothing, in her 2015 launch, Clinton explained that it was her mother who taught her something similar. “Everyone needs a chance and a champion,” Clinton said.

Standing out

Nothing that any of these women said was remotely offensive, belittling, or derogatory, which already exceeds the standard that Trump sets every day. But nor was anything especially memorable, other than the size of Harris’ crowd, the blizzard for Klobuchar’s event (where, as a true Minnesotan, she skipped the gloves), and Warren’s tale of potty training her 2-year-old with the help of M&M’s (for the sake of child care to go to law school, people, don’t judge).

Barely two years after Clinton conceded her race to Donald Trump, with accusations of sexism heavy in the air, it’s clear that being a woman in 2020 is not only not a handicap for Harris, Warren, Klobuchar and Gillibrand, it is an obvious strategic advantage. Millions of suburban women gave control of the House to Democrats in the midterms, after all, in a bid to slow Donald Trump’s roll.

But the irony of so many Democratic women running for president this cycle is that they will all need to do much more going forward to distinguish themselves from each other for voters, above and beyond making history. And they’ll need to show how they’re different enough from Clinton that they can win over people who didn’t vote for Clinton in 2016.

After more than two centuries of America’s presidential fields looking like the men’s room at a golf club, the chance to see six women, four of them senators, announce their bids for president in a single year is a watershed achievement in itself. But as any woman, especially Hillary Clinton, can tell you, “firsts” and achievements don’t win races. Only 270 electoral votes can do that. How will these women get there? The next 18 months will tell.

Patricia Murphy covers national politics for The Daily Beast. Previously, she was the Capitol Hill bureau chief for Politics Daily and founder and editor of Citizen Jane Politics. Follow her on Twitter @1PatriciaMurphy.