AP

Sen. Patty Murray (D-WA), chairwoman of the Democratic Senatorial Campaign Committee.

The head of Senate Democrats' campaign efforts said Wednesday that she considered victory in November to be nothing less than keeping control of the upper chamber.

"I was asked by the majority leader and the members of my caucus to take on the job of running the Democratic Senate campaign committee and keeping the majority for Democrats in the Senate, said Washington Sen. Patty Murray, the head of the Democratic Senatorial Campaign Committee (DSCC). "That's what I call a win."

Murray outlined for reporters on Capitol Hill the status of Democrats' efforts to keep control of the Senate; Republicans need to achieve a net gain of four seats to take control of the chamber when its next session convenes in January.

Murray said she wouldn't name Democrats' chances -- "
I am not from Nevada, so I don't do odds," she said -- but argued that her party was well-positioned to defend their majority.

She lauded candidates' hard work and fundraising to stay competitive with their Republican challengers. While Democrats must defend a total of 23 seats, their candidates have remained competitive in states like Montana and North Dakota, among other states.

Republicans point out that there are a number of scenarios in which they could achieve the victories they need to make Republican Leader Mitch McConnell (KY) the majority leader come next November.

The GOP's waged its campaign in part by tying Democratic candidates to President Obama, especially in more Republican-leaning states where the president is less popular, and Mitt Romney is likely to win this fall.

Murray sidestepped questions about whether Obama should avoid appearing with some of those vulnerable senators.

"We're in the last 100 days and in any election you have to really focus on where you need to be, and President Obama is rightly doing that in his top states," she said.

But the Washington Democrat effusively praised some of the most vulnerable-seeming candidates. Murray boldly predicted that her Missouri colleague, Sen. Claire McCaskill, was "absolutely going to win that race," despite trailing her three Republican challengers in the most recent polling.

The biggest variable? Murray said it would be the impact of Republican super PACs that have already blanketed airwaves with criticism of Democratic incumbents and candidates.

"The only thing that stands between me and a long, good night of sleep is the outside money that is coming into these races," she said.