SPRINGFIELD — Is a line in Illinois’ Constitution instructing the General Assembly to pass a balanced budget a requirement, or a suggestion?That question was recently posed to the Supreme Court, woven into a case that challenged the constitutionality of taxpayer-funded abortions through Medicaid. Although the state’s highest court declined to hear the case, the leading expert on Illinois’ governing document said the language is indeed a mandate.The Thomas More Society, a conservative law firm based in Chicago, filed a …