Biden pledged to make Roe v. Wade "the law of the land." Abortion-rights supporters want more.

Former Vice President Joe Biden pledged his support for legal abortion on Monday evening, promising to make Roe v. Wade "the law of the land" if he's elected president. But abortion-rights supporters say a promise to protect Roe isn't enough to ensure access to the procedure.

During a town hall on Monday, an audience member asked Biden for his "particular plan to protect women's reproductive rights in the U.S." given the likely confirmation of conservative Amy Coney Barrett to the Supreme Court.

"Number one, we don't know exactly what she will do, although the expectation is that she very well may overrule Roe, and the only responsible response to that would be to pass legislation to make Roe the law of the land," Biden said. "That's what I would do."

President Trump responded Tuesday morning on Twitter, writing, "Wow. Joe Biden just took a more Liberal position on Roe v. Wade than Elizabeth Warren at her highest."

But abortion-rights supporters say that Biden's position — likely a reference to codifying the Supreme Court decision into law — is baseline for the Democratic Party. To be sure, every major Democratic candidate for president made the same promise on the campaign trail and most, including Biden's running mate Senator Kamala Harris, went several steps further, offering voters specific plans to expand abortion access.

The landmark 1973 decision in Roe v. Wade legalized abortion nationwide, but subsequent Supreme Court decisions gave states the authority to regulate the procedure as long as the restrictions don't pose an "undue burden" on the patient. Since 2011, states have passed more than 450 laws regulating and restricting access to the procedure. 

"Roe is important, but now we really think of that as the floor not the ceiling," said Destiny Lopez, co-director of the All* Above All Action Fund, an abortion-rights group, in a telephone interview with CBS News. 

Even with Roe intact today, states in the South and Midwest have enacted hundreds of regulations and restrictions that have limited patients' access to abortion, including mandatory waiting periods, insurance coverage barriers, and gestational bans. Last year, Missouri nearly became the first state to be without an abortion provider and earlier this year, Texas completely stopped abortion for nearly four weeks, claiming the procedure wasn't "essential" and should be suspended amid the coronavirus pandemic. In June, the Supreme Court narrowly struck down a Louisiana abortion regulation that could have closed all three of the state's abortion providers.

"Even with Roe in place, so many people are unable to get the abortion care they want," said Megan Donovan, senior policy manager at the Guttmacher Institute, a reproductive health research group that supports access to abortion, in an email to CBS News. "We can start with protecting Roe, but the fight cannot end there."

The Biden campaign has offered few details on its plans to protect access to abortion. In addition to codifying Roe into law, which would require support from the U.S. Senate, Biden has also pledged to restore funding to Planned Parenthood and other providers that left the Title X program after the Trump administration's so-called "gag order" on abortion. Last summer Biden also abandoned his support for the Hyde Amendment, a 1976 rule that prohibits the use of federal dollars from funding abortion services except in the cases of rape, incest or life-threatening circumstances. Those positions are all ones held by every major Democratic presidential candidate in this year's primaries.

Lopez, whose group specifically focuses on repealing the Hyde Amendment, was optimistic that Biden's campaign had a larger plan.

"I think and hope there's a more expansive view on the ticket on what it means to have access to abortion," Lopez said. "While keeping abortion legal is good, it doesn't assure that people can access abortion."

Carol Tobias, president of the National Right to Life Committee, an anti-abortion rights political group, said the Democratic Party has gone too far in its support for abortion access and wasn't surprised by Biden's promise to codify Roe. But for Tobias as well as abortion-rights supporters, Roe isn't the end game.

"If Roe is overturned, that doesn't make abortion illegal, it makes abortion a 50 state battle," Tobias said. "And I know that pro-lifers will keep working."