In this day and age, why do presidential campaigns insist on going negative?

The short answer is simple: Because it works.

It works especially when the voters are in a lousy mood and worried about the future direction of the country.

I find it amusing when the media criticize John McCainJohn McCainMcCain says he hasn't met with Trump since inauguration Overnight Defense: General warns State Department cuts would hurt military | Bergdahl lawyers appeal Trump motion | Senators demand action after nude photo scandal Senate lawmakers eye hearing next week for Air Force secretary: report MORE for being “too negative.”

He ran a positive campaign pretty much all spring and for most of the summer. He did his biography tour. He laid out his plans on healthcare, on energy, on the economy, on national security. And the media pretty much ignored him.

He says a few truthful things about Barack ObamaBarack ObamaFBI Director Comey visits White House AIPAC must reach out to President Trump Tea Party Express backs Trump’s ObamaCare bill MORE, and he gets tons of media attention. And he gets condemned.

To be ignored or to be condemned? Tough choice.

But for McCain, he has no choice. He has to risk the media’s wrath in order to build the case against Obama.

Obama hasn’t shied away from saying negative and false things about McCain.

He says that that McCain will continue all the policies of the Bush administration, that his will be a third Bush term.

That is completely false and Obama knows it. McCain’s approach to governance is completely different from Bush’s. Just look at his record and the fact that many conservatives are very nervous about a McCain presidency.

McCain is bipartisan where Bush is hyper-partisan. McCain has clear differences from Bush on healthcare, on global warming, on campaign finance reform, on torture, on a host of other issues.

Obama says repeatedly that McCain wants to keep us in Iraq for 100 years, as if McCain is some war-monger who cares little for our troops.

That, of course, is not true. McCain was talking about keeping our troops out of harm’s way in Iraq, just as they are out of harm’s way in Germany, Italy, Turkey, Japan and other places around the globe. But Obama loves to willfully distort McCain’s comments, because he thinks it works with voters.

That is true negative campaigning.

What McCain is doing is raising some valid questions about Mr. Obama and his record.

The fact that Obama is against more drilling for oil in America.

The fact that Obama will sharply raise taxes on job creators.

The fact that Obama decided not to visit wounded troops in Germany, but instead addressed 200,000 Germans in Berlin.

That fact that Obama was wrong on the surge policy and won’t admit it.

Should McCain make all of these points himself? Maybe not. But somebody has to make them.

And until McCain has a running mate, the job will fall to him.

My advice to McCain is pick a vice president who is willing to talk about Obama’s thin résumé and left-wing positions. And do it quickly.