Rasmussen released a survey of 700 likely voters taken in Missouri on October 15th (?) and released on October 17th. The margin of error is 4%.

McCain – 46%

Obama – 52%

Other – 0%

Not sure – 2%

This poll shows that Obama’s lead is expanding when compared to the Rasmussen October 12th and October 5th Missouri presidential polls, though the sample sizes and methodologies (that is, including third party candidates or not) appear to be different.