A Section 1983 Primer (4): Causation and the Mt. Healthy Burden-Shift Rule
As in ordinary tort law, a person who is sued under section 1983 for damages must be shown to be responsible in order to held liable. In other words, that person must have caused the plaintiff’s constitutional deprivation. But in certain section 1983 cases involving impermissible motivation, such as public employee equal protection and First Amendment cases, there are complications arising out of the burden-shift rule of Mt. Healthy Bd. of Education v. Doyle, 429 U.S. 274 (1977).
Typical Fact Pattern
Suppose a public employee is discharged and believes the discharge was impermissibly motivated either because of race (equal protection) or because what he or she said (First Amendment). It turns out that even if the plaintiff can prove this, he or she will not necessarily win on the merits and recover damages because of the Mt. Healthy burden-shift rule.
How the Mt. Healthy Burden-Shift Rule Works
Under Mt. Healthy, (1) the plaintiff has the burden of proving by a preponderance of the evidence that the impermissible motive was a substantial factor (not the but-for cause or the sole cause) for the discharge. Once the plaintiff does this, the plaintiff has made out a prima facie case and will prevail on the merits (2) unless the defendant can prove by a preponderance of the evidence that there was a permissible factor–such as insubordination, incompetence or the like–that also played a role in the discharge and–here’s the key– (3) the plaintiff would have been discharged anyway even in the absence of the impermissible motive.
This is the Mt. Healthy burden-shift that, if carried, means that the defendant is not liable on the merits: no constitutional violation, no damages and no attorney’s fees. It is a powerful affirmative defense.
The Scope of the Mt. Healthy Burden-Shift Rule
The Mt. Healthy burden-shift applies in mixed-motive cases. It is inapplicable where the plaintiff proves by a preponderance of the evidence that the impermissible motive was the sole cause for the discharge.
Significantly, it is also inapplicable in after-acquired evidence cases. Suppose, for example, that in the course of section 1983 litigation involving allegations of unconstitutional discharge, the defendant discovers that the plaintiff lied on his or her employment application and can demonstrate that the plaintiff would therefore not have been hired in the first place. This is not a Mt. Healthy burden-shift case because it is not a mixed-motive case. The defendant’s liability for the constitutional deprivation is unaffected.
This is not to say, though, that the defendant’s after-acquired evidence is irrelevant: it goes to the extent of recoverable damages. The defendant is liable for the damages–lost pay, for example–resulting from the unconstitutional discharge up to the date of discovery of this evidence but not for any such damages thereafter. The Supreme Court made this clear in McKennon v. Nashville Banner Publishing Co., 513 U.S. 352 (1995).
Note, finally, that the Court’s recent decision in Gross v. FBL Financial Services, 557 U.S. — (2009), which held that a mixed-motive instruction is never proper in Age Discrimination in Employment Act cases, does not govern section 1983 litigation and thus does not change the Mt. Healthy burden-shift rule. See 557 U.S. at — n.6.