Iowa and Colorado, typically battleground states in presidential and congressional campaigns, each have more registered voters than they have adults over the age of 18 living in the state, according to a conservative watchdog group’s analysis.

Poll worker Daniel Andrews shows Jessica Roberts how to use an electronic voting machine at Patrick Henry High School in Roanoke, Va., on Tuesday, Nov. 5, 2013. Democrat Terry McAuliffe and Republican Ken Cuccinelli are running succeed term-limited Gov. Bob McDonnell for a four year term starting in January. A third candidate, libertarian Robert Sarvis, is also on the ballot. (AP)

Poll worker Daniel Andrews shows Jessica Roberts how to use an electronic voting machine at Patrick Henry High School in Roanoke, Va., on Tuesday, Nov. 5, 2013. (AP)

The same is true of Washington, D.C., which is set to hold a primary in its mayoral election next week.

Judicial Watch is threatening legal action against the two states and the nation’s capital if immediate steps aren’t taken to clear the voter rolls of dead voters, voters who have moved away or voters that that have become ineligible for other reasons.

States and municipalities are required to keep legitimate roils under Section 8 of the National Voter Registration Act, better known as the Motor Voter Law enacted in 1993.

Robert D. Popper, former deputy chief of the voting section within the Justice Department’s civil rights division, said he was part of five lawsuits during the Bush administration over allegations of improper voter list maintenance since he was hired in 2005.

“In the six years of the Obama administration, there’s been not a single lawsuit,” Popper, now a senior attorney for Judicial Watch, told reporters in Washington on Monday.

Section 7 of the NVRA made voter registration available at local departments of motor vehicle locations and other government offices. Section 8 required a system in place to ensure the voting rolls were kept clean to preserve election integrity.

“There has been to my knowledge a demonstrated lack of interest in the Justice Department in pursuing these lawsuits,” Popper said. “In fact, the one claim that had anything to do with this list maintenance coming out of this Justice Department concerned the lawsuit that it commenced and then lost in which it tried to force the state of Florida to stop removing non-citizens who are on the voter rolls in the run up to the 2012 elections. Other than that, the Obama administration has no interest in pursuing Section 8 lawsuits.”

In Iowa, there were more people registered to vote than were living in the state in at least 24 counties in 2012, up from 10 counties in 2010. In Colorado, that number increased from 10 counties in 2010 to 22 counties in 2012, according to Judicial Watch. The data was compiled by comparing U.S. Census data with U.S. Election Assistance Commission information.

In a letter to top election officials, Judicial Watch said it will file lawsuits if Iowa, Colorado and the District do not correction violations of Section 8 of the NVRA within 90 days.

“Specifically, we ask you to: 1) conduct or implement systemic, uniform, nondiscriminatory program to remove from the list of eligible voters the names of persons who have become ineligible to vote by reason of change in residence,” the letter says, “2) complete this program no less than 90 days prior to the November election; 3) conduct or implement additional routine measures to remove from the list of eligible voters the names of persons who have become ineligible to vote by reasons of death, change in residence, or a disqualifying criminal conviction, and to remove noncitizens who have registered to vote unlawfully.”

A spokesman for Colorado Secretary of State Scott Gessler told TheBlaze the office is “continuing to review the letter.”

“The secretary is committed to accurate voting rolls and continues to ask the legislature for the resources to clean the rolls,” Gessler spokesman spokesman Rich Coolidge told TheBlaze. “Unfortunately, the legislature in Colorado would rather have an honor system for voting than an accurate system.”

D.C. Board of Elections spokeswoman Tamara Robinson said the District is part of the Electronic Registry Information Center, or ERIC, a system established by the Pew Trust to allow nine states and jurisdictions to share information about individuals on voter rolls.

“The District of Columbia Board of Elections takes every step possible to make sure the voter rolls are accurate,” Robinson said.

While Robinson said the District has found cases of people being registered in two or more areas, she said there has never been evidence that they tried to vote more than once.

“Voters should be confident in the integrity of the D.C. elections,” Robinson said. “There have not been any issues of voter fraud whatsoever.”

A spokesman for Iowa Secretary of State Matt Schultz could not be reached for comment Monday.

“Dirty voter rolls mean dirty elections,” Judicial Watch President Tom Fitton said during Monday’s press conference. “Many states are shirking their legal responsibilities to maintain clean voter rolls. This undermines confidence in our election system and outrageously, the Obama Justice Department simply refuses to enforce the federal law that requires states to take responsible steps to clean voter rolls. Judicial Watch is now doing the job of the U.S. Justice Department.”

A Justice Department representative did not respond to phone and email inquiries from TheBlaze.

“We have an election in the District of Columbia next week. We can’t have confidence in the integrity of that election as a result of the mess that the districts voting rolls are in,” Fitton said. “It’s not too late for the District to take steps now, at least to make sure for instance, dead people aren’t on the rolls. When you have people on the rolls who aren’t supposed to be there, that’s an invitation for voter fraud. In the age of mail-in ballots and easy absentee ballots, that’s where you have rife opportunities for voter fraud.”

Judicial Watch filed a similar lawsuit against the state of Ohio in August, and reached a settlement in January in which Ohio agreed to require county boards of election to send accuracy surveys to the state, participate in the Interstate Voter Registration Cross-Check, and to keep better track of death information.

Earlier this month, Judicial Watch also sent letters to California, New Mexico, Kentucky, West Virginia, North Carolina, Alabama, Mississippi, Missouri and Illinois notifying them of “apparent problems” and asking these states to provide records of steps taken to assure the accuracy of the voter lists.