Updated: 11:18 a.m.As expected, Rep. Marion Berry (D) announced Monday morning that he will step down from his northeast Arkansas seat at the end of his seventh term. Berry is now the sixth House Democrat in a competitive district to announce retirement plans in the past two months.In a release Monday, Berry, 67, cited health concerns as the reason why he is leaving Congress.As a lifelong farmer, time has taken its toll on my health and I am no longer able to serve the district with the vitality I once possessed, Berry said. Therefore, I have decided not to seek reelection in 2010. I am at perfect peace with this decision and look forward to returning to the farm and my home state of Arkansas.With Berry out of the race in a district that Sen. John McCain (R-Ariz.) won by 21 points in the 2008 presidential contest, the Republican field which until now had included only little-known farm broadcaster Rick Crawford is expected to grow. Already the names of state Rep. Davy Carter (R) and state Sen. Johnny Key (R) are being floated as potential candidates in the open-seat race. Jonesboro businessman and former GOP gubernatorial nominee Woody Freeman is another name being circulated in Washington, D.C., and Arkansas Republican circles.But top Democrats said they expect to hold Berrys seat come November.We are confident that this district will continue to elect a Democratic candidate who shares Representative Berrys values and commitment to standing up for the middle class in these challenging economic times, Democratic Congressional Campaign Committee Chairman Chris Van Hollen (Md.) said in a statement Monday.Democratic strategists have identified former Arkansas Democratic Party Chairman Jason Willett and former Berry staffer Chad Causey as potential candidates to replace him.State Attorney General Dustin McDaniel (D) said Monday that he would not run.Democrats point out that in 2006, every Democratic candidate for statewide office exceeded 60 percent of the vote in the 1st district. And in the more Republican-friendly year of 2002, Sen. Mark Pryor (D) won the 1st district with 58 percent of the vote in his campaign to unseat then-Sen. Tim Hutchinson (R).