DES MOINES, Iowa (AP) — Democratic Rep. Bruce Braley on Thursday became the first Iowan to announce plans to seek the U.S. Senate seat being vacated by Sen. Tom Harkin after 30 years.

Braley, a four-term House member from Waterloo, announced his plans in an email to potential supporters, describing his goal of representing all Iowans as "a big responsibility." The decision came less than two weeks after Harkin, a fellow Democrat first elected to the Senate in 1984, said he had decided against seeking a sixth term in next year's election.

Iowa's first open Senate seat in 40 years is seen as a jump ball for both parties and a chance for Republicans who need a net gain of six seats in the U.S. Senate to seize the majority.

"This is a very important race, not just in this state but nationally as well," Iowa Republican fundraiser Nick Ryan said. "The road to a Republican majority begins in Iowa."

Braley said last week he met with Senate Majority Leader Harry Reid and leaders of the Democratic Senatorial Campaign Committee in Washington and that they had encouraged him to run. He has been huddling with family and talking to Iowa Democrats and advisers since Harkin's Jan. 26 announcement.

"There appears to be a lot of support for Braley," Iowa Democratic Party Treasurer Ken Sagar said. Other possible candidates, including former first lady Christie Vilsack whom aides have said is weighing a campaign, had not as of Thursday ruled out running

Republican U.S. Reps. Steve King and Tom Latham have also been weighing campaigns but neither has taken formal steps to establish a campaign fundraising committee.

Harkin, with $2.7 million in his campaign war chest, would have had an edge next year, despite being a target of national Republicans in earlier re-election bids. Harkin easily beat little-known Cedar Rapids conservative Republican Christopher Reid in 2008. Continued...