One Senate seat is NOTHING compared to the presidency. Just look at what Bush has been able to frustrate and do over the last four years even when Democrats controlled the Congress. I'd tae a 1% greater chance to win the White House over a 100% chance of one less Senate seat (and whatever candidate we put up to replace Warner in Virginia would still have an excellent chance to win the seat, especially with an Obama-Warner heading the ticket).
Nah. With over 60 in the Senate and a majority in the House you control the agenda.
Do you think Roberts and Alito would not be on the Supreme Court right now if we had one more Senator? Would we be out of Iraq right now if we had one more Senator?
One Senator is nothing compared to the Presidency in terms of accomplishing a progressive agenda.