Bowing to political realities, Democratic presidential candidate John Kerry (search) has canceled plans to begin broadcasting television commercials in Arizona, Arkansas, Louisiana and the perennial battleground of Missouri.

The decision to shrink his political playing field reduces Kerry's strategic options -- at least for now -- in the homestretch of the campaign. George W. Bush (search) won all four states in 2000, and Kerry can't win the White House without taking one or two of them away from the Republican incumbent.

The ads were scheduled to begin airing Oct. 5 as part of a $5 million investment through Nov. 2, but campaign advisers concluded Kerry isn't doing well enough in the states to justify the cost.

The campaign, which has reserved commercial time in 20 states through Election Day (search), notified television stations in the four states that Kerry would not follow through on his plans for the first week of October.

Plans are still in place to air ads starting the second week of October, campaign officials said, but those will likely be tabled, too.

The officials, who spoke on condition of anonymity, said Arizona, Arkansas and Louisiana are unlikely to see Kerry ads unless there is a major shift in the campaign's dynamics. Missouri is still the subject of debate inside the campaign, with some advisers pushing to advertise in the traditional swing state.

With its burgeoning exurbs and rural areas turning more Republican every day, Missouri cannot be won by Kerry in a close race, some advisers have concluded. But some think it's important for the Democrat to spend money there, forcing President Bush to defend the GOP turf.

Bush and the Republican National Committee (search) have been advertising moderately in Arizona and Missouri. With Kerry chased from those states, Bush can shift their budgets -- $330,000 this week alone -- to states that Democratic presidential nominee Al Gore won four years ago.

Kerry spent about $15 million in the four states, half of it in Missouri, trying to put them in play. It was part of a strategy to stretch the battlefield into GOP territory, from Virginia and North Carolina in the South to Arizona in the Southwest and Nevada in the West.

Constantly shifting their strategies, both campaigns recently increased their ad budgets in West Virginia and Colorado. Bush has boosted his ads in Minnesota, Maine and Oregon -- all states won by Gore that Kerry can't afford to lose.

Ohio and Florida, with a combined 47 electoral votes, offer Kerry his best hope of claiming territory won by Bush in 2000. After that, the options dwindle to a few small states: New Hampshire, Nevada, West Virginia and Colorado.

Kerry ads are running in 14 of the 20 states in which he reserved commercial time. His schedule calls for ads to begin airing next month in Maine and North Carolina.

Because of population shifts since 2000 that favor Republicans, Kerry could win every state taken by Gore in 2000 and would have just 260 electoral votes, 10 short of winning the presidency. Gore lost to Bush by five electoral votes, 271-266.