>For example, liberals decry Mississippi's 15-week abortion ban as "imposing religious beliefs." So why do highly secular countries like France and Denmark draw the line at 13 or 14 weeks?

Yes, people don't realize that Roe v. Wade made abortion far more permissible in the US than in almost every other Western country. The only exception I am aware of is Canada, which because of a series of accidents ended up with no abortion laws at all.