If they are in the same position as a man, doing the same work, then yes.
Is that really so hard to comprehend?
Being a European social democrat who is for all kind of funky shit I am probably quite a bit to the left of the ordinary American liberal ... but with wage regulation you make a step you really wanna think twice about.
For young female white-collar workers there is also the pregnancy issue. If your company invests into your skills it wants a return on that investment and seniority wage patterns are one way to tie employees to the company. So a totally non-sexist employer might be either hesitant to higher women for a white-collar job or price the pregnancy risk in which implies a lower wage.
I am not saying that this actually explains wage discrimination but this highlights the problem of forcing equal wages.
Over here a stupid court stopped gender discrimination in insurance. So women who have fewer car accidents than men will have to pay higher fees now and men who do have a shorter life expectancy will have to pay higher life insurance fees.
This is clearly an example of political correctness gone crazy, being unable to distinguish between actual discrimination and statistical discrimination