Seven in 10 Americans believe Roe v. Wade should stand, according to new data from a Wall Street Journal/NBC News poll, as the landmark Supreme Court abortion-rights ruling turns 40 on Tuesday.

That is the highest level of support for the decision, which established a woman's right to an abortion, since polls began tracking it in 1989. The shift is mostly the result of more Democrats backing the decision—particularly Hispanics and African-Americans—and a slight uptick in support from Republicans.

But the poll showed a consistent tension in Americans' attitudes toward the decision. Almost seven in 10 respondents say there are at least some circumstances in which they don't support abortion.

Some 31% of respondents in the poll said abortion should always be legal, and 9% believed it should be illegal without any exceptions. Between those two opinions are the 23% who thought it should be legal most of the time, but with some exceptions, and the 35% who felt it should be illegal except in circumstances of rape, incest and to save a woman's life.

Read more at the Wall Street Journal.