senate is talking about whether to repeal the don't ask, don't tell pollcy. joel brown has more. >> reporter: senators are set to cast a key vote later today on whether gay men and women will be allowed to serve openly in the u.s. military. democrats need 60 votes to move forward to repeal the don't ask, don't tell law. most republicans are lining up to stop the measure in its tracks. john mccain argues military commanders believe it's too soon. >> all of them wanted a complete study on the effect of moore rail and -- morale and battle readiness. >> reporter: defense secretary robert gates who supports getting rid of the policy ordered a study on how repealing it would affect the armed forces. the results are due in december, but elections are coming in november. both sides see a chance to score political points in the don't ask, don't tell. even pop stars are lending their voice to the discussion. >> don't ask, don't tell is wrong. >> reporter: lady gaga is better known for her outrageous outfits but she's take an strong stand on don't ask, don't tell, calli