Senator Warren states that pay discrimination has long-lasting effects. Is this a valid argument supported by accurate evidence?

Yes.

Explanation:

Yes, Senator Warren stands victorious in successfully presenting the long-lasting effects brought in by wage discrimination through offering sufficient evidence to validate his claim. She substantiates her claim by indicating the factual consequences associated with the pay inequality (as reflected by the phrase that 'Women ... earn only 77 cents ... every dollar a man earns') by stating that 'Pay inequality also means a tougher retirement for women.' He also says that 'unequal pay makes it harder for them to pay back student loans' which implies that their future becomes difficult (as another long-term effect of unequal pay). Warren's evidence not only authenticates her claim but also convinces the readers to pay attention and believe in the author's concern towards the serious problem of such wage discrimination.