For example, during the debate, McCain did mention how he and Obama differ on tax policy. At one point, McCain even compared Obama to Herbert Hoover. "My friends," he said, "the last president to raise taxes during tough economic times was Herbert Hoover, and he practiced protectionism, as well."

McCain later said: "I've got some news, Sen. Obama -- the news is bad. So let's not raise anybody's taxes."

But McCain never got specific on capital gains and dividends, and he failed to educate voters on just how important investment is to healthy job-creating businesses.

Ditto for McCain's proposed corporate tax cut. The senator wants to slash the business tax rate from 35 percent to 25 percent. It's an excellent plan. But McCain doesn't explain how two-thirds of the benefits of a corporate tax cut go to the workforce through higher wages, with the rest then going to shareholders. He also doesn't point out that ordinary folks actually pay the corporate tax, since firms pass this tax cost along in the form of higher prices. So McCain could, in fact, call a corporate tax cut a consumer tax cut. But he's not doing this.

McCain also needs to put investors on red alert about Obama's middle-class tax cut. The Illinois senator's huge government-spending plans will overwhelm his ability to cut taxes for 95 percent of the people. In fact, McCain needs to remind voters that Bill Clinton made exactly the same promise as a candidate in 1992 before he broke it as president in 1993.

Time's running out. The investor class vote -- which still looks up for grabs -- has simply got to be a McCain priority if he is to win in November. Rag Mayur doesn't have his October polling results in yet, but he thinks the race will be much tighter than mainstream pundits believe. Message to Sen. McCain: The investor vote could well tip the balance.