The United States Supreme Court, in the case of Shelby County, Alabama v. Holder, Attorney General, Et al., ruled that Section 4(b) of the Federal Voting Rights Act is unconstitutional.  Section 4(b) contained the formula that placed a jurisdiction under the mandate of Section 5.  Section 5 requires local jurisdictions to submit their proposed changes to voting-related laws to either the U.S. Department of Justice or the Federal District Court for the District of Columbia for preclearance before such laws can go into effect.  While the Supreme Court allowed Section 5 to stand, it appears that its effect has been suspended unless Congress acts to replace it.

Section 4(b) provides (See: http://www.justice.gov/crt/about/vot/42usc/subch_ia.php#anchor_1973b):

• (b) Required factual determinations necessary to allow suspension of compliance with tests and devices; publication in Federal Register

  The provisions of subsection (a) of this section shall apply in any State or in any political subdivision of a State which (1) the Attorney General determines maintained on November 1, 1964, any test or device, and with respect to which (2) the Director of the Census determines that less than 50 per centum of the persons of voting age residing therein were registered on November 1, 1964, or that less than 50 per centum of such persons voted in the presidential election of November 1964. On and after August 6, 1970, in addition to any State or political subdivision of a State determined to be subject to subsection (a) of this section pursuant to the previous sentence, the provisions of subsection (a) of this section shall apply in any State or any political subdivision of a State which (i) the Attorney General determines maintained on November 1, 1968, any test or device, and with respect to which (ii) the Director of the Census determines that less than 50 per centum of the persons of voting age residing therein were registered on November 1, 1968, or that less than 50 per centum of such persons voted in the presidential election of November 1968. On and after August 6, 1975, in addition to any State or political subdivision of a State determined to be subject to subsection (a) of this section pursuant to the previous two sentences, the provisions of subsection (a) of this section shall apply in any State or any political subdivision of a State which (i) the Attorney General determines maintained on November 1, 1972, any test or device, and with respect to which (ii) the Director of the Census determines that less than 50 per centum of the citizens of voting age were registered on November 1, 1972, or that less than 50 per centum of such persons voted in the Presidential election of November 1972.

  A determination or certification of the Attorney General or of the Director of the Census under this section or under section 1973d or 1973k of this title shall not be reviewable in any court and shall be effective upon publication in the Federal Register.

This formula was reauthorized by Congress repeatedly, most recently in 2006 for an additional 25 years.  The counties that were subject to preclearance review under Section 5 in Florida because of this formula were: Hillsborough, Monroe, Collier, Hardee and Hendry.   

Florida newspaper articles on the case include TBT, Miami Herald, News-Press.  The Attorney General issued a press release in response.