Why does John McCain‘s campaign strategy these days seem to consist almost entirely of propagating falsehoods?

For example, there was this item from NBC‘s FirstRead blog yesterday:

McCain and his campaign repeated at least two lines of attack against Obama, which when first said in early July, were called “bogus,” “wrong,” “inflated” and “misleading” by independent fact checkers.

At his town hall today, McCain repeated that Obama wants to raise taxes on those making as little as $32,000 a year and in his campaign’s response to Obama’s event in Springfield, Mo., today, repeated that “…Obama’s bad judgment led him to vote in support of higher taxes 94 times….”

Repeating a claim that has already been demonstrated to be false can only be described as a deliberate lie.

There was also the accusation that McCain and his campaign — with the able assistance of barbecue-lovers throughout the media — milked for several days about Barack Obama and wounded U.S. troops in Germany.

For four days, Sen. John McCain and his allies have accused Sen. Barack Obama of snubbing wounded soldiers by canceling a visit to a military hospital because he could not take reporters with him, despite no evidence that the charge is true.

The attacks are part of a newly aggressive McCain operation whose aim is to portray the Democratic presidential candidate as a craven politician more interested in his image than in ailing soldiers, a senior McCain adviser said. They come despite repeated pledges by the Republican that he will never question his rival’s patriotism.

The essence of McCain’s allegation is that Obama planned to take a media entourage, including television cameras, to Landstuhl Regional Medical Center in Germany during his week-long foreign trip, and that he canceled the visit when he learned he could not do so…. In fact, there is no evidence that he planned to take anyone to the American hospital other than a military adviser…

On Monday, McCain once again repeated what has become his staple lie:

John McCain again pushed for offshore drilling Monday, and suggested it could provide relief to American consumers “within a matter of months.”

“There are some instances within a matter of months, they could be getting additional oil. In some cases, it would be a matter of a year,” McCain said at a press conference in Bakersfield, California. “In some cases, it could take longer than that depending on the location and whether or not you use existing rigs or you have to install new rigs. But there is abundant resources in the view of the people who are in the business that could be exploited in a matter of months.”

As is well known — to everyone, including the McCain campaign — the federal Energy Information Administration has previously estimated that if the offshore drilling moratorium were lifted today, “production would not be expected to start before 2017″ and offshore drilling “would not have a significant impact on domestic crude oil and natural gas production or prices before 2030″.

McCain himself, in a weak moment, has acknowledged that offshore drilling would at best have only a psychological impact on crude oil prices today and gas prices at the pump. More importantly, since McCain is not authorized to make official statements on behalf of himself, his grand vizier Douglas Holtz-Eakin, has acknowledged that new offshore drilling would have no immediate effect on supplies or prices.

So, coming back to the original question, why adopt wholesale lying as a campaign strategy?

Because it works, that’s why; enough of us are dumb enough to buy the lie:

As gas prices remain above $4 a gallon in most of the Bay Area, Californians are more open to the idea of offshore drilling for oil than they have been in the past.

A slim majority — 51 percent to 45 percent — approve of offshore drilling, according to a survey by the Public Policy Institute of California. It’s the first time since the institute began asking the question in 2003 that more residents favor drilling than oppose it. A year ago, 41 percent favored drilling.

Still, the issue appears driven by partisan inclinations. More than three-quarters — 77 percent — of Republicans support offshore oil drilling, up from 60 percent a year ago. Only 35 percent of Democrats approve of drilling, but that’s up, from 29 percent a year ago. Less than half of independents — 44 percent — are in favor, up from 33 percent last year.