The Democratic Party platform only re-affirms the current status of U.S. law - essentially that a woman has the unequivocal right to choose an abortion until such time as the fetus becomes “viable”, or in exceptional circumstances (mother’s health, etc.), afterwards.

In addition, the Democratic Party platform includes a strong statement in favor of women who choose not to have an abortion:

The Democratic Party also strongly supports a woman’s decision to have a child by ensuring access to and availability of programs for pre- and post-natal health care, parenting skills, income support, and caring adoption programs.

Meanwhile, the Republican Party platform radically diverges from current law - advocating that in no case should a woman be allowed to choose an abortion, even within the first days of pregnancy (when the “fetus” is no more than a cluster of tissue cells); even cases where she has been raped; and even when her own life is at risk.

See here

To my ears, the Republican position is the one that seems “extreme”.