In the latest Rasmussen Reports survey of Missouri's competitive race for the U.S. Senate, Republican Senator Jim Talent narrowly leads his Democratic challenger, State Auditor Claire McCaskill, 43% to 40% (see crosstabs).

A week before the current survey, Senator Talent announced his opposition to a ballot measure that would forbid the state government from imposing restrictions on stem cell research that is allowed federally. Talent's sometimes fluctuating criticism of such research continues to spur controversy. McCaskill supports the ballot measure.

Our previous election poll in Missouri found McCaskill up by one percentage point. Every measure of this race suggests it is close.

This is the sixth time in seven polls that Talent and McCaskill have been within three percentage points of each other. In the last four polls, each candidate has been slightly ahead two times. Both candidates have reached 46% in one poll this calendar year and both have stayed between 40% and 43% in the other four polls conducted since January.

The closeness of the race is also highlighted by the rolling average our last three polls in the state. That measure shows McCaskill with a whisker-thin lead of 42% to 41%. The candidates have never been more than a point apart when using this measure.

Interestingly, voter support for both candidates has steadily declined since the beginning of the year. Talent and McCaskill have both dropped a total of four percentage points since January.

Crosstabs are available for Premium Members.

The power of incumbency is clearly helping Talent stay even in this race. When asked whether they trust Republicans or Democrats more on several high-profile issues, Missouri voters give Democrats the edge across the board. This is true on the economy, national security, energy policy, immigration, and Iraq.

On these same five issues, President Bush draws consistently negative reviews. More than 50% say the President is doing a poor job on energy, immigration, and Iraq.

Crosstabs are available for Premium Members

Visit our Election Polls page to see a summary of our latest state-by state polling. Rasmussen Reports is polling every Senate and Governors' race at least once a month this year.