WASHINGTON -- For 50 years the "one person, one vote" principle has been used to try to equally distribute political power by counting all people in states and cities, and then putting them into election districts of roughly the same size.
The mathematics of power may be about to change in a way that could shift political clout away from the fast-growing Latino communities in states such as California, Texas and Florida and move it to suburban and rural communities.
The Supreme Court said Tuesday it will hear a Texas case to decide whether voting districts should continue to be drawn by using Census data on total population, including immigrants here legally and illegally, or by counting only citizens who are eligible to vote, as conservative challengers are now seeking.
Election law analysts were surprised by the court's move. Despite decades of decisions on voting rights, the justices have steered clear of clarifying whether election districts should have an equal number of residents or an equal number of eligible voters.
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The justices announced Tuesday they would decide whether states "deny voters an equal right" when they count all the residents, including immigrants, in drawing their election districts.
The court said it will hear the case in the fall and rule early next year.
The case was brought to the high court by Edward Blum, a conservative activist who two years ago won the Supreme Court ruling that struck down part of the Voting Rights Act. Blum also launched a constitutional challenge to the affirmative-action policy at the University of Texas that is still pending.
"My interest is in restoring the original principles of the civil rights movement of the 1960s," Blum said Tuesday. "Your race and ethnicity should be not be used to help or harm your position in life."
He has tried for more than 15 years to persuade the high court to clarify the "one person, one vote" rule. "I'm hopeful and confident we will prevail," he said.
Blum sued on behalf of Sue Evenwel, a county chairwoman for the Texas Republican Party. She lives in mostly rural Titus County in east Texas.
Her state Senate district had 533,010 citizens of voting age in 2011. However, another Senate district had 372,000 citizens of voting age.
The appeal in Evenwel vs. Abbott argues that her right to an equal vote is being denied because Texas officials relied on the census data to balance the districts. Requiring states to switch to counting only citizens will "ensure that voters are afforded the basic right to an equal vote," her lawyers said.
In the 1960s, the high court adopted the "one person, one vote" rule to require that election districts be roughly equal in population. Prior to that time, many states gave each county a representative in the state Senate, thereby giving thinly populated rural areas the same clout as major cities.
This rule is based on the equal protection clause of the 14th Amendment, and it is applied to all state elections, including for state legislators, county boards, city council or local school boards. The appeal does not directly challenge congressional districts, but if the justices rule broadly, it could also apply to members of Congress.
At least once a decade, these districts may be redrawn based on new census data. The U.S. Census Bureau seeks to count the total population, including noncitizens and immigrants in the country illegally.
This data is considered reliable. Stanford law professor Nate Persily, an expert on voting, questioned whether comparable figures exist to tally the actual number of citizens.
"We don't have a national list of citizens," he said. The data cited in the Texas case comes from a Census survey of about 2 percent of households that counts citizens. "If you are only counting 2 percent of the households, there will be wild inaccuracies. It would be crazy to force states to draw districts with this data," he said.
The appeal in the Texas case noted that same issue arose in Los Angeles County in 1990.
By a 2-1 vote, the 9th Circuit Court of Appeals upheld a ruling that required the county board of supervisors to redraw its districts and create one with a Latino majority. In dissent, Judge Alex Kozinski questioned the premise of relying on the total population figures, rather than on the count of citizens who were eligible to vote.