TALLAHASSEE — As Florida's next election draws closer, U.S. Attorney General Eric Holder has a stern warning for Gov. Rick Scott: We're watching you.

Holder sent a scathing letter to the Republican governor that cited "troubling" voting changes and said the Justice Department is "carefully monitoring" Florida's upcoming elections.

"We will not hesitate to use all tools and legal authorities at our disposal to fight against racial discrimination, to stand against disenfranchisement and to safeguard the right of every eligible American to cast a ballot," Holder wrote.

Scott called Holder's action "pure politics" and said it was "just them trying to help Charlie Crist," his likely Democratic opponent in November.

Repeatedly chastising Scott, Holder wrote: "During your tenure, your state has repeatedly added barriers to voting and restricted access to the polls."

He noted that Scott voted to make it harder for felons to regain their voting rights after they have completed their sentences, and he cited three actions by Scott's chief elections official, Secretary of State Ken Detzner, including an attempted purge of suspected noncitizens from voter rolls that was suspended after a mutiny by county election supervisors.

Detzner also denied the city of Gainesville's request to use the University of Florida student union for early voting and told election supervisors not to allow voters to submit absentee ballots at remote dropoff sites. The latter action appeared directed at Pinellas Supervisor of Elections Deborah Clark, who still uses the sites after a visit by a state observer showed no problems.

"I read the (Holder) letter, and I certainly understand why anyone would be concerned because of actions taken by the Legislature and the secretary of state," Clark said. She said she foresees no problems with the 2014 election because she and other supervisors "put the brakes" on actions such as the purge of suspected noncitizens.

In his letter, Holder also cited restrictions on early voting hours in a bill Scott signed in 2011. But last year, the Legislature expanded the maximum early voting days from eight to 14 and gave supervisors more flexibility in choosing sites.

Holder acknowledged that step but added: "I have grave concerns that there remains a troubling pattern in your state of measures that make it more difficult, not easier, for Floridians to vote."

The controversial 2011 elections bill, which Holder called a "disaster," also made it harder for third-party groups to register voters, which prompted a successful lawsuit by the League of Women Voters and other groups.

Deirdre Macnab, president of the League of Women Voters of Florida, said Holder's warnings are welcomed and justified.

"Anyone who cracks open a history book on Florida elections should not be surprised," Macnab said. "We should all be encouraged by the Justice Department's scrutiny."

The 2011 voting changes followed Barack Obama's Florida victory in 2008, which some Republicans blamed on then-Republican Gov. Crist's executive order to extend early voting hours.

With new early voting restrictions in place in 2012, Florida saw huge lines in some locations, especially in South Florida, and the outcome of the presidential election was delayed, leading to a wave of negative publicity and criticism that Republicans tried to manipulate the outcome.

Amid the backlash, lawmakers reversed course and Scott approved the changes.

The Justice Department declined comment on its July 21 letter, saying it speaks for itself, though Holder has been aggressive on voting issues and voting rights cases. His office made filings in cases in Wisconsin and Ohio on Wednesday, but Scott appears to be the only governor to receive such a strongly worded letter.

At a campaign event in St. Petersburg on Friday, Scott had this to say:

"I mean, this is pure politics. In 2011 we changed our voting laws and they were precleared by the Justice Department. In 2012 we had record turnout, we had record numbers of voters in 2012. But then in 2013 we increased the number of voting locations and voting hours, we shortened the ballot. So does the White House think we should change those? This is just them trying to help Charlie Crist, the failed candidate that lost jobs and cut education funding."

Added Scott's campaign manager, Melissa Sellers: "It isn't surprising that the same president who used the IRS to persecute his political opponents is now using his attorney general to try the same tactic."

Times staff writer Katie Mettler contributed to this report.