“Pretty please” hasn’t gotten District leaders and activists very far on one seemingly easy White House ask: Putting D.C.’s “Taxation Without Representation” license plates on presidential motorcade vehicles, including Barack Obama’s limousine.

So D.C. Vote, the city’s premier voting-rights advocacy group, has decided to take advantage of the White House’s new web petition process. The group is asking city residents and other supporters of voting rights to support a request that Obama install the “Taxation” tags ahead of the Jan. 21 inauguration parade in order to “demonstrate the injustice experienced by more than 600,000 Americans who live in the capital city.”

The deal is this: Get 25,000 web signatures in 30 days, and the issue will receive an official White House response. Sometimes that means actual results (e.g., White House beer recipe). Sometimes that means a polite “no, thank you” (e.g., Texas secession.)

D.C. Vote is asking supporters to use social media and neighborhood listservs to spread the word.

“Taxation” tags have been D.C.’s standard license plates since 2000. They appeared briefly on the presidential motorcade late in Bill Clinton’s term. But under George W. Bush, the White House went with the optional “Taxation”-less plates, and Obama has not changed course.

James Jones, D.C. Vote’s communications director, said the group is “very grateful” for Obama’s support of voting-rights efforts generally. “Displaying the Taxation Without Representation plate is simply an expression of the truth about DC’s political status,” he said in a statement.