from today's Nikkei（追記あり）

民主党代表に小沢氏
47票差菅氏破る　政権と対決姿勢
菅・鳩山氏要職に　きょう人事骨格

言葉：
代表：President, the representative
民主党：the Democratic Part of Japan
小沢氏：Ichiro Ozawa（呼び捨てが普通）
四七票差：by the margin of 47 votes
政権：ruling parties(the administration等というより、この場合は政権を握っている政党のことと考えていい）
対決姿勢：stance facing the ruling paries
要職：key posts
骨格：outline
人事：reshuffle of key posts in the party,key post's reshuffle ( of (,or in) the party)

Then
Ichiro Ozawa was nominated( elected) as President of Democratic party of Japan. He defeated Naoto Kan by the margin of 47 votes in the party's presidential election. Ichiro Ozawa made clear his idea that the party should face the ruling parties from now on. Concerning how to treat two party's members,Naoto kan and Yukio Hatoyama,he will likely to place both of them to the party's key posts.Outline of its post reshuffle will be clear today.

追記：
by the margin of 47 votesは　by a margin of 47 votes の方がいいのかな。差はmajority やleadを使う手もあるみたいだが、marginが一番解りやすそうである。
with a lead of 47 votes
by ( with ) a mojority of 47 votes

concerning は
as to
with regard to
in regard to
等たくさん代替的な言葉はある。
代表選挙をthe party's presidential election としたが、presidential は「大統領の」と思われる可能性が高いとすれば、representative election とした方がベターかも知れない。