Tucson, Arizona - Democrats were set to hammer Donald Trump Friday on the divisive issue of abortion, calling him the "architect" of a US healthcare crisis, as the party sees an opening with voters ahead of the November presidential election.

Vice President Kamala Harris was due to campaign in the battleground of Arizona just days after that southwestern state's conservative supreme court rolled back reproductive rights to the Civil War era, saying an 1864 ban on abortion was valid.

The ruling, which rendered almost all pregnancy terminations illegal with no exceptions for rape or incest, made Arizona the latest state to severely limit the procedure.

That comes after the US Supreme Court – with a conservative majority thanks to three Trump appointments – overturned a decades-old national right to choose.

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"We all must understand who is to blame," Harris is expected to say at a campaign event in Tucson.

"It is Donald Trump who, during his campaign in 2016, said women should be punished for seeking an abortion," she was to say. "Donald Trump is the architect of this health-care crisis. And that's not a fact he hides. In fact, he brags about it."

While a clear majority of Americans support abortion rights, many Republicans, particularly religious conservatives, see banning it across the US as a top priority.

Since the US Supreme Court ruling in 2022, bans or tough restrictions have come into force in a number of conservative states.

But when the issue has been on the ballot, voters have sided with the right to choose – even in typically "red" states like Kansas.

Democrats see the issue as a vote winner and are seeking to yoke Trump, the de facto Republican Party presidential nominee, to the bans.

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In the wake of the Arizona court ruling this week, the party is splashing a huge sum of money on an advertising campaign in the must-win state – aimed at key Democratic target groups: young people, women, and Latino voters.

They hope that this will help drive turnout and support for President Joe Biden in the November 5 election, even as many polls show the 81-year-old trailing his populist predecessor.

"If Donald Trump gets the chance, he will sign a national abortion ban," Harris will say in Tucson, according to Politico. "How do we know? Look at his record. Congress tried to pass a national abortion ban before, in 2017, and then-President Trump endorsed it."

Trump, for his part, has sought to thread the needle, boasting to evangelicals of his role in overturning Roe vs. Wade, while lamenting at other times that rulings like the one in Arizona have gone "too far."