Some decisions have both lawful and unlawful motives, and statutes differ on the consequence.
The general discrimination statute permits a claim where a protected characteristic was a motivating factor, even if other factors also motivated the decision. If the employer proves it would have taken the same action regardless, the remedy is limited to declaratory relief, injunctive relief and attorney fees — not damages, back pay or reinstatement.
Retaliation claims under the same statute require but-for causation rather than motivating factor, following judicial construction.
Age claims require but-for causation.
Disability claims are split among the circuits on the applicable standard.
Evidence. A mixed motive instruction does not require direct evidence; circumstantial evidence suffices.
Practical consequence. The framework matters most at trial, in the instruction and the verdict form. Where a same-decision defence is available, the verdict form should be structured to permit the jury to find both that the characteristic was a motivating factor and that the same decision would have been made.
For employers. Contemporaneous documentation of the lawful reason, and evidence that the decision process was underway before any protected activity, is what supports the same-decision defence.