Clean Air, Strong Economies Act or the CASE Act - Prohibits the Environmental Protection Agency (EPA) from lowering its existing national ambient air quality standards (NAAQS) until at least 85% of counties that are in nonattainment areas (counties that are exceeding the limit) have attained the standard.

Requires the EPA, in promulgating a primary or secondary NAAQS for ozone, to:

• only consider a county to be a nonattainment area on the basis of direct air quality monitoring (rather than modeling);
• take into consideration feasibility and cost; and
• include in the regulatory impact analysis for the proposed and final rule at least one analysis that does not include any calculation of benefits resulting from reducing emissions of any pollutant other than ozone.