An indication of how important Missouri’s U.S. Senate race is in the eyes the power brokers in Washington. Democrat Senate candidate Claire McCaskill will deliver Saturday’s weekly Democratic Radio Address. The topic of the speech: stem cell research. It’s an issue which has become a divisive one in McCaskill’s challenge to incumbent Republican Senator Jim Talent. McCaskill supports efforts to lift restrictions on federally-funded embryonic stem cell research. Talent opposes the idea. The McCaskill speech, in its entirety, will be available on the Missourinet webpage shortly after its scheduled broadcast time of 10:07 a.m. Missouri time.