Senator Joseph R. Biden Jr. has a pugnacious style on the campaign trail.

By MARK LEIBOVICH

FLAT ROCK, Michigan - As the economy reels, Senator Joseph R.
Biden Jr. - the Other Running Mate - has been vigorously attacking Senator John McCain across battleground states. It is not clear who has noticed.
“John is so out of touch, he just has no idea,” charged Mr. Biden, the Democratic vice-presidential nominee, who called his “old, dear friend” someone who “just doesn’t think,” who is behaving in a repugnant manner and who is peddling “Republican garbage.”
The older woman who introduced him at a rally here called Mr. Biden’s Republican counterpart, Governor Sarah Palin of Alaska, a “bucket of fluff,” and he rewarded the woman as he took the microphone with an “I love you” and a gentle kiss on the head.
But the reality for Mr. Biden is that Ms. Palin is receiving much more attention. It is not like in August, when reporters swarmed Mr. Biden’s Delaware home and delegates swooned at the Democratic convention.
He is now struggling to break through in a race marked by historic firsts, political celebrities and charismatic newcomers - none named Joe Biden.
The Democratic campaign of Senator Barack Obama was hoping to reintroduce Mr. Biden as a running-mate attack dog. But his penchant for verbal rambling ensured that much of the attention he drew was unwanted: he said wealthy Americans had a “patriotic” duty to pay more taxes, a remark the McCain campaign mocked relentlessly.
Yet Mr. Biden has also become a fascinating spectacle in his own right.
He is a distinctive blend of pit bull and odd duck, capable of blurting out pretty much anything - including out-of-nowhere comments (pivoting midspeech to say “Excuse my back!” to people seated behind him) and goofy asides (tapping a reporter’s chest and telling him, “You need to work on your pecs.”)
However, Mr. Biden’s role is serious: to pulverize Mr. McCain, lend foreign policy heft to Mr. Obama and be his campaign’s main ambassador to two at-risk constituencies: former supporters of Senator Hillary Rodham Clinton and blue-collar Democrats. He speaks to working-class voters in harsh language of their economic trials, and summons easy rage at earsplitting volumes.
Mr. Biden might seem like an afterthought on the national airwaves, but his fiery partisan attacks can clearly resonate close up. Voters, including some who came in unconvinced about Mr. Obama, have given him generally good reviews.
“Biden is a guy who I really believe, who really seems like he is going to help us out,” said Sheryl Kline, a loader for the United Parcel Service who attended a rally in Maumee, Ohio. “He sounds like someone who knows how we’re struggling.”