While the administration continues to deflect suggestions that the Massachusetts race may be a referendum on the Obama presidency, Republicans say the symbolism of Brown's victory is hard to deny.
"As we look forward to the midterm elections this November, Democrats nationwide should be on notice: Americans are ready to hold the party in power accountable for their irresponsible spending and out-of-touch agenda, and they're ready for real change in Washington," National Republican Campaign Committee chairman John Cornyn said after Brown's victory.
Massachusetts, where registered Democrats outnumber Republicans by more than three to one, has long been a Democratic stronghold, sending two Democratic senators to Washington for each of the past 31 years.
The last time a Republican senator was elected in Massachusetts was November 1972, when Sen. Edward Brooke won the coveted seat.
Sen. Robert Menendez, D-N.J., the chairman of the Democratic Senate Campaign Committee said the message voters sent in Brown's victory was not lost on the party.
"I have no interest in sugar coating what happened in Massachusetts," Menendez said. "There is a lot of anxiety in the country right now. Americans are understandably impatient. The truth is Democrats understand the economic anger voters feel, that's in large part why we did well in 2006 and 2008.
"In the days ahead, we will sort through the lessons of Massachusetts: the need to redouble our efforts on the economy, the need to show that our commitment to real change is as powerful as it was in 2008, and the reality that we cannot take a single thing for granted and cannot afford even a second of complacency."
Although Democrats no longer have the 60 votes needed to thwart a Republican filibuster, they still maintain the largest Senate majority either party has enjoyed since 1979 and have the ability to pass legislation through reconciliation, a process which bypasses normal Senate rules by only requiring 50 votes.
Several congressional sources say that idea is off the table for the pending health care legislation, because it would mean having to start over and could risk losing some Democratic moderates, which in turn could cost Democrats the bill altogether. But a few Democrats have suggested reconciliation is be a viable option.
House Speaker Nancy Pelosi, D-Calif., told reporters Monday, "Let's remove all doubt, we will have health care -- one way or another."
Another option: The House could pass the Senate version of the health care bill verbatim, which would send the legislation to the president's desk without protracted negotiations.
"Whether there are 59 seats in the Senate or 60, we still have to work hard to get our economy back on track. We still have to work hard to make the promise of affordable, accessible health care for millions of Americans a reality," Gibbs said earlier today.
Meanwhile, public support for the president and Democrats' plan to overhaul the health care system continues to wane.
In an ABC News/Washington Post poll released today, 51 percent of Americans said they oppose health care overhaul efforts, with only 44 percent in favor.