Democratic U.S. Rep. Ron Barber and Republican Martha McSally have kicked off the 2014 election cycle in southeastern Arizona's Congressional District 2.

If both get through their parties' primary elections, the race will be a rematch of the 2012 contest, which Barber won by a slender margin and then only after a week of ballot counting.

McSally announced last week that she is running against Barber, and she filed as a candidate.

Shortly after her announcement, the National Republican Congressional Committee released results of a poll showing the two essentially in a dead heat, within the margin of error. The NRCC said that polling result shows Barber is vulnerable in the next election.

Barber responded with a fundraising request of his supporters, saying in an email that McSally will represent the Tea Party in the campaign.

In the two other Southern Arizona congressional districts, Republicans have also announced challenges to the Democratic incumbents, Ann Kirkpatrick in District 1 and Raúl Grijalva in District 3.

To qualify for the primary election ballot, candidates must gather signatures on nominating petitions that will be due May 28, 2014. The primary election will be Aug. 26, 2014 and the general election Nov. 4, 2014.