Plagiarism
The Clinton machine is using a "charge" of plagiarism against Obama, and is getting the desired results. All of the McCainstream Media, both left and right, are helping to carry the charge.
It's really an irrelevant charge within the world of politics, because nearly all politicians grab good lines from other politicians. Original writing is simply not part of the job description for a good leader; you're more likely to inspire people with well-tested lines. Only a few pols (Disraeli, Churchill, Jefferson, Lincoln) are fully original writers. All the rest are happy copiers, and the [living] sources don't seem to object.
But plagiarism
does matter within two other professions: Academia and journalism. Doing your own research, and attributing sources accurately, are definitely part of the job description for professors and reporters. Even within those worlds the charge is only used in exceptional cases, though .... both academia and journalism have tight fraternities with strong leftist tendencies, and both have audiences which don't share the leftist tendencies. Now and then a prof or a reporter will crank out propaganda so crude or heavy-handed that the audience (college alumni or newspaper readers) will start withdrawing their support for the institution. In those cases, plagiarism gives the management a functional method to fire the heavy-handed propagandist. If they fired her honestly, the fraternity would rock the institution with shouts of McCarthyism! McCarthyism! McCarthyism! McCarthyism! McCarthyism! McCarthyism! McCarthyism! McCarthyism!
So they use plagiarism as the stated reason, because it's a meaningful offense to the fraternity members, who are serious professionals as well as serious Communists.
The Clinton machine is following the same gambit. They know that the two Leninist fraternities ... who naturally prefer Obama as the more orthodox leftist ... will carry the charge against Obama, and may even lose some of their love for him in the process.
The voters don't give a rip either way.