Call CNN's voter hotline with your concerns or problems with voting.

(CNN) – Ordinarily, there’s a world of difference between Sen. Barack Obama, the Democratic nominee for president, and former Georgia congressman Bob Barr, the Libertarian Party’s nominee. But voters tell CNN that machines in Knox County, Tennessee had them confused about which of the two men they were voting for.

“On the summary page, after I voted for Barack Obama, when you summarize before you hit ‘cast ballot,’ it says ‘BAR’ for my vote,” Russ Manning of Knoxville, Tennessee said in one of the calls CNN received about Knox County. With Barr’s name also on the ballot, Manning was concerned that machine was about to incorrectly record his vote for Obama as a vote for Barr. “And, so I had to go back and forth several times to make sure I was voting for the right person. With everybody else on the ballot, the names are completely spelled out but you only get ‘BAR’ for Barack Obama and ‘BOB’ for Bob Barr as I finally figured out.”

Local election officials in Knox County are aware of the issue and are working to inform voters and poll workers about that the unusual references are actually to the first three letters of each man’s first name. "'It’s because of the electors,’” Greg Mackay, the Knox County administrator of elections, told the Knoxville News Sentinel recently. "'It’s just on the president. It says ‘electors for’ on the summary page and the first three letters for the candidate of your choice.’” Mackay also told the newspaper he has received two or three complaints about the summary page of the county’s voting machines during the first week of early voting.

If you have any problems or concerns about voting, CNN would like to hear about them. Call CNN’s voter hotline at 1-877-GOCNN-08 (1-877-462-6608) to report your problem.

Hillary Clinton got some extra superdelegates Wednesday.

(CNN) — Tennessee Rep. John Tanner announced Wednesday he is backing Hillary Clinton's White House bid.

Tanner, a Democrat representing Tennessee's 8th District, is one of the more than 700 party superdelegates who will ultimately decide which candidate wins the Democratic presidential nomination.

"In my opinion, the best person to lead this critical effort is Hillary Clinton," Tanner said in a statement released by the Clinton campaign. "Hillary is a smart, pragmatic leader who understands the grave situation our country faces, with a $9 trillion debt, much of which is borrowed from foreign countries. Now, more than ever, our nation needs a leader like Sen. Clinton who can work with others to return to fiscal sanity."

Clinton won the state of Tennessee with 54 percent of the vote on February 5.

To track the Tennessee primary results county-by-county, click here: Tennessee

(CNN) — Hillary Clinton’s campaign is pointing to her victories in the Republican-heavy states of Tennessee, Arkansas and Oklahoma as proof she can win in areas far from the coasts. “With these first two victories, Hillary Clinton has demonstrated that she can compete and win in red states,” read a Tuesday night campaign statement.

The Obama campaign has pointed to its major endorsement haul from Democratic elected officials in majority-Republican states.

Sen. Clinton spent many years as Arkansas’ first lady. Tennessee allows Democrats, Republicans and Independents to vote in its Democratic primary, but according to CNN’s exit poll, Obama actually scored marginally higher than Clinton among independents who chose to vote in the Tennessee primary (CNN did not poll Republican voters in the Democratic primary).

Oklahoma, for its part, has a “closed” Democratic primary, meaning that only registered Democrats can vote; so there’s no way to know what choice Oklahoma’s registered Republicans would make.

– CNN Political Producer Alan Isenberg

Some polling places in Tennessee and Arkansas were forced to close early due to tornadoes

NEW YORK (CNN) – The Arkansas and Tennessee secretaries of state were forced to close some polling places earlier than expected Tuesday after several destructive tornadoes tracked through both states.

Tennessee State Elections Director Brook Thompson told CNN that "a couple of precincts" were closed early after "local authorities told us to relocate our workers" to safety. Polling places in McNairy, Tipton, Fayette and Dyer counties were closed around 6:30 p.m. CT (7:30 p.m. ET), Thompson said.

"I don't think this affected a large number of voters," he said. "I think everyone was trying to get home."

Thompson said there is no plan to reopen the polling places, which were scheduled to close at 7 p.m. CT (8 p.m. ET).

Natasha Naragon, spokeswoman for the Arkansas secretary of state, told CNN that polling places closed early in Baxter and Craighead counties, while they “have heard reports of several closing in northern Conway County.”

Naragon said that they have not heard any reports of people unable to vote. Polls in Arkansas were scheduled to close at 7:30 p.m. CT (8:30 p.m. ET).

CNN projects that Hillary Clinton won the Arkansas and Tennessee primaries, while Mike Huckabee captured the Arkansas primary.

Related: Watch the tornado touch down in Tennessee

(updated at 9 p.m. with additional reporting)

– CNN Political Editor Mark Preston

To track the Tennessee primary results county-by-county, click here: Tennessee