As the 40th anniversary of the Roe v. Wade Supreme Court decision takes place on Tuesday, a majority of Americans – for the first time – believe abortion should be legal in all or most cases, according to a new NBC News/Wall Street Journal poll.

What’s more, seven in 10 respondents oppose Roe v. Wade being overturned, which is the highest percentage on this question since 1989.

“These are profound changes,” says Republican pollster Bill McInturff, who conducted this survey with Democratic pollster Peter D. Hart and his colleagues.

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McInturff adds that the abortion-related events and rhetoric over the past year – which included controversial remarks on abortion and rape by two Republican Senate candidates, as well as a highly charged debate over contraception – helped shaped these changing poll numbers.

“The dialogue we have had in the last year has contributed … to inform and shift attitudes.”

View the poll results here

Jan. 22, 1973: NBC's Garrick Utley and Betty Rollin report on the landmark decision by the Supreme Court on the issue of abortion.

The 1973 Roe v. Wade decision established a woman’s constitutional right to an abortion, at least in the first three months of pregnancy.

According to the poll, 54 percent of adults say that abortion should be legal either always or most of the time, while a combined 44 percent said it should be illegal – either with or without exceptions.

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That’s the first time since this poll question was first asked in 2003 that a majority maintained that abortion should be legal. Previously (with just one exception in 2008), majorities said abortion should be illegal.

In addition, a whopping 70 percent of Americans oppose the Roe v. Wade decision being overturned, including 57 percent who feel strongly about this.

That’s up from the 58 percent who said the decision shouldn’t be overturned in 1989; the 60 percent who said this in 2002; and the 66 percent who said this in 2005.

By comparison, just 24 percent now want the Roe v. Wade decision overturned, including 21 percent who feel strongly about this position.

Much of this change, the NBC/WSJ pollsters say, is coming from African Americans, Latinos and women without college degrees -- all of whom increasingly oppose the Supreme Court decision being overturned.

The NBC/WSJ poll was conducted Jan. 12-15 of 1,000 adults (including 300 cellphone-only respondents), and it has a margin of error of plus-minus 3.1 percentage points.

Related: 40 years after landmark decision, restrictions on abortion grow