In 2002, the Supreme Court heard oral arguments in Utah v. Evans, a case brought by the State of Utah to contest the practice of imputation in the census, which had cost Utah a congressional seat. Utah lost the case by a narrow margin, but important issues regarding legal interpretations of statistical terminology were brought to the fore. In this talk, I'll discuss my role as a Utah's principal expert witness in the case, outlining the statistical arguments raised, as well as giving an insider's view of what it's like to work as an expert witness in a fast-tracked Supreme Court lawsuit.