WRAPUP 3-Obama, Clinton trade charges in speech flap

(Adds Clinton commennt, paragraphs 3-4)

By John Whitesides, Political Correspondent

NILES, Ohio, Feb 18 (Reuters) - Democrats Barack Obama and Hillary Clinton traded charges on Monday over Obama's uncredited use of a friend's lines in a speech, one day before the presidential contenders meet in a critical showdown in Wisconsin.

Pointing toward Tuesday's primary, the two camps battled over a recent Obama speech using words from Massachusetts Gov. Deval Patrick -- a friend and political ally of Obama. Obama said he should have credited Patrick but dismissed the controversy as no big deal.

Hillary Clinton, speaking to reporters in Madison, Wisconsin, aboard her plane, was asked about the issue.

"If your whole candidacy is about words, they should be your own words. That's what I think," she said.

Clinton spokesman Howard Wolfson said the use of the lines called into question Obama's rhetoric -- one of the Illinois senator's biggest selling points.

"Senator Obama is running on the strength of his rhetoric and the strength of his promises and, as we have seen in the last couple of days, he's breaking his promises and his rhetoric isn't his own," Wolfson said.

The exchanges came before Tuesday's votes in Wisconsin and Hawaii, which will allocate a combined 94 delegates to the August convention that selects the Democratic presidential nominee in November's election.