## Facts

- A union was certified as the collective-bargaining representative for Curtin Matheson Scientific, Inc.’s employees under the NLRA.
- After certification, the union called a strike.
- During the strike, the employer hired 22 striker replacements, who became a majority of the bargaining unit.
- Relying on the fact of replacement hiring and limited information from one replacement worker, the employer concluded the union had lost majority support.
- The employer withdrew recognition and refused to bargain with the union.
- The union filed an unfair-labor-practice charge alleging unlawful refusal to bargain under NLRA § 8(a)(5) and (1).
- The NLRB’s approach to inferring replacements’ union sentiments had changed over time; by the time of the Board’s decision, it used a “no-presumption” approach requiring case-specific evidence.

## Issues

1. Whether the NLRB acted within its discretion under the NLRA by refusing to presume that striker replacements oppose the incumbent union when evaluating an employer’s claimed good-faith doubt of majority support.
2. Whether the Board reasonably found the employer lacked sufficient objective evidence to rebut the post-certification presumption that the union retained majority support.

## Decision

- The Supreme Court reversed the Fifth Circuit and upheld the NLRB’s “no-presumption” approach.
- The Court held the Board acted within its statutory discretion in declining to presume striker replacements oppose the union.
- The Court deferred to the Board’s policy judgment as rational and consistent with the NLRA, even though it reflected a shift from prior Board practice.
- Applying the Board’s approach, the employer’s reliance on replacement status and limited anecdotal information did not provide a sufficient objective basis for good-faith doubt.
- The Board’s order requiring the employer to recognize and bargain with the union upon request was entitled to enforcement.

## Legal Principles

- A certified union has an irrebuttable presumption of majority support for one year; after that, the presumption is rebuttable.
- After the first year, an employer may rebut the presumption only with a good-faith doubt of majority support grounded in sufficient objective evidence.
- The NLRB may choose, as a matter of policy, not to apply any categorical presumption about striker replacements’ union sentiments and instead determine sentiment case by case.
- Courts owe substantial deference to NLRB policy choices that are rational and consistent with the NLRA, including reasoned departures from earlier Board approaches.
- The mere fact that replacements make up a majority of a unit, without more, does not necessarily establish an objective basis for withdrawing recognition.

## Conclusion

The Court upheld the NLRB’s discretion to reject an evidentiary presumption that striker replacements oppose an incumbent union and required employers to show specific, objective evidence of lost majority support before withdrawing recognition and refusing to bargain.


NLRB v. Curtin Matheson Sci., Inc., 494 U.S. 775 (1990)