Conservative Morality Is Based On Narrow, Unsupported Ideology

The slogan for today's Republican Party. They have
been hijacked by conservative Christians who
reject science-informed morality.

The USA was NEVER "Great", it has been a work-in-progress from its beginning. Conservatives want to "conserve" an imperfect past, whereas, progressives look forward to improving the well-being of all (link). One has to be blind to reality not to see the slow and unsteady progress toward greater recognition of basic human rights, much of which has been opposed by religious dogma. The case can be made that this is because morality pertains to the conduct of human affairs and relations between persons, while religion primarily involves the relationship between human beings and a transcendent reality (link).

It is clear that morality is not objective (no evidence of a God), but subjective in each normal human from biological and social factors. Thus, an agreement is difficult. However, if at least most of us can agree with the general definition of morality as well-being and flourishing, humanity can maximize such with information from science. Evidence shows that morality without a God (secular) is superior (link). 

Applying the above to the question of abortion:

• Religions can't agree on when a human person begins, and science shows that life does not begin but it has flowed continuously since the first chemicals emerged with the traits we call life.
• There IS agreement that a woman is a person. Persons have bodily autonomy.
• One has the right to believe anything they want but not the right to impose it on others. The law must reflect what the majority believes is moral.