If the Democrats fail to win the senate back in 2004 there is absolutely no chance they can do it in 2006. Just look at what is ahead in 2006:
There will be 31 Senate races in 2006. The democrats and republicans will have to defend 16 and 14 seats respectively with Jeffords being the sole independent in the senate.
The democratic seats are:
CA - Feinstein - D
CT - Lieberman - D
DE - Carper - D
FL - Nelson - D
HI - Akaka - D
MD - Sabranes - D
MA - Kennedy - D
MI - Stabenow - D
MN - Dayton - D
NJ - Corzine - D
NM - Bingaman - D
NY - Clinton - D
ND - Conrad - D
VT - Jeffords - I
WA - Cantwell - D
WV - Byrd - D
WI - Kohl - D
Republican seats are:
AZ - John Kyl - R
IN - Lugar - R
ME - Snowe - R
MI - Lott - R
NE - Burns - R
NV - Ensign - R
OH - DeWine - R
PA - Santorum - R
RI - Chafee - R
TN - Frist - R
TX - Hutchison - R
UT - Hatch - R
VA - Allen - R
WY - Thomas - R
I just can't see where there can be a D pickup opportunity. May be Ensign in NV? DeWine in OH? Looks very grim.
So, it is either take back the senate now or wait till 2008.