Kerry spent around $5 million, Hillary Clinton spent $34 million. Her opponent was far less a threat. Why did she spend about 7 times as much? Part of the money Kerry spent on ads in the primary was done because there were few competitive races and many people did not know he had an opponent. To put the spending in context, Kennedy in 2006 did not have a primary challenge, but spent slightly over $7 million - against a hapless opponent. (
http://www.fec.gov/press/press2007/partyfinal2006/senpty.pdf This looks unofficial, but it was where the NYT link in my earlier post takes you if you click "chart") Kerry spent LESS than Kennedy, who spent only one fifth of what Clinton did, but I guess you missed Kennedy's ads. (I can't find Kerry's 2002 FEC numbers.) I didn't miss HRC's incessant 2006 ads because I get NYC tv.
You say Beatty got in a few blows - the fact is that he went for the Palin approach and often ignored the questions to simply attack the Senator, who responded well on every single question. None of the attacks gained traction and Kerry, on the spot, calmly and definitively debunked a huge number of dishonest charges. Kerry sinking to Beatty's level would have been less effective than what he did - answering the questions and making a case for himself. When you are over 30 points ahead and and one of the top 12 Senators, attacking your opponent is really not needed and can be counterproductive. Beatty's negatives increased after the debates, while his positives stayed about the same. He looked and sounded completely unlikable. He ended up getting just 30.9% of the vote. Given that % and the % he got against Delahunt, he is hardly "commanding".
If Kerry would have had no debates with Beatty and run no ad you would be the first to post that he thought he was entitled to run. As to your thought that Kerry felt even the least bit threatened - the experts quoted in this Boston Globe article disagreed.
http://www.boston.com/news/local/massachusetts/articles/2008/11/05/kerry_easily_defeats_beatty_to_win_a_5th_term/It also meant that Beatty did not make a case for himself. What the debate showed was as the Patriot Ledger said when they endorsed Kerry:
"Kerry’s Republican opponent this year, Jeff Beatty, takes a back seat to no one in his understanding of terrorist threats and homeland security. But Beatty has displayed an alarming lack of understanding, knowledge or interest in nearly every other issue from education to energy to the needs of the fishing industry."
http://www.patriotledger.com/opinions/x409583935/OUR-OPINION-Kerry-for-Senate-Focused-on-the-nowI really fail to see what was "commanding" about a candidate who reacted to a mild barb from Kerry's spokesperson referencing the New York Yankees as the New Jersey born and bred Beatty's favorite team by launching an attack that the Onion would have thought over the top.
http://www.politickerma.com/jeremyjacobs/1486/beatty-camp-reacts-yankees-charge-accuses-kerry-smears He was also wrong on his facts - as Kerry pointed out in the debate - The treasury secretary (Paulson) bailed out AIG, not the Congress - it was before the big $700 million bailout and neither Kerry had any AIG at the time - THK had some earlier on the snapshot Senate disclosure form. Kerry, not Beatty, was commanding in explaining that - as Beatty mumbled in the background.