The University of Texas' admissions office is 1,522 miles from the front door of the John A. Wilson Building, the home of the District's government.

That didn't stop the city, though, from joining Maryland, 13 other states and the U.S. Virgin Islands last week in filing a 26-page brief before the U.S. Supreme Court to defend the school's race-conscious admissions policy.

But while states regularly file about 50 amicus curiae -- Latin for "friend of the court" -- briefs each year, scholars aren't sure of their impact.

Robert Bork, a former U.S. solicitor general and a Supreme Court nominee in 1987, told The Washington Examiner that although the filings can be helpful gauges of public opinion, most do little to influence the court's legal thinking.

"It does not add much substance, but it does indicate public support for and against," Bork wrote in an email. "But on the other hand, political arguments should not be made before the court because they are not the court's business. They are a court of law, not of politics. Most amicus briefs are a waste of time in terms of the law."

A survey of former Supreme Court clerks about a decade ago found that most briefs are at least read, but they don't play a significant role in deciding a case's merits unless the matter is particularly technical.

Dan Schweitzer, the Supreme Court counsel for the nonpartisan National Association of Attorneys General, said the state-backed briefs play a crucial role, though, as the nine justices consider which cases to hear. According to Schweitzer's statistics, the Supreme Court accepts about 45 percent of the cases that states, using amicus briefs, ask the court to review. The justices, however, reject thousands more petitions annually from others seeking the court's time.

The District's filing in the University of Texas case was not the first proceeding into which the city inserted itself recently. Among other matters, the city has filed briefs before the court on cases focused on health care reform and immigration policy, both of which the court ruled on in June.

"We have urged the Supreme Court to uphold efforts by the University of Texas to diversify its student body," D.C. Attorney General Irvin Nathan said of the city's latest filing. "Such a decision would encourage states to continue experimenting with constitutional practices that maximize educational opportunities for all."

People familiar with the city's filing habits said D.C. joins a case when the attorney general's office feels it will significantly impact the District's legal interests. City lawyers draft few of the briefs, though, and usually join with other states to make the District's views known to the court.

"D.C. has not been an active writer of amicus briefs, but as a practical matter, most states have not been writers," Schweitzer said. "Most states -- most of the time -- are joiners, not writers."

The District last filed a brief of its own in March 2010 in a case that began in D.C. Superior Court and focused on whether private citizens could prompt prosecutions for criminal contempt. Ultimately, the Supreme Court did not rule on the case and said it had "improvidently" agreed to review the matter.