Financial markets took those words as a sign of new action, probably as early as the Fed's next meeting of the rate-setting Federal Open Market Committee on Sept. 12-13.
"The odds of the Fed doing something in September are greater today than they were yesterday," said Mark Vitner, senior economist for Wells Fargo Securities in Charlotte, N.C. "It seems clear to me that they're not focusing on the unemployment rate but the persistently high unemployment that is likely to do long-term damage to the economy."
If the Fed does take action, it would come less than two months before the Nov. 6 election, and history suggests that what the Fed does during an election is always viewed through a political prism.
President George H.W. Bush famously blamed his 1992 re-election defeat to Bill Clinton on then-Fed Chairman Alan Greenspan's failure to cut interest rates in a slow economy.
"Traditionally the Fed has been very careful about making moves near to an election, to avoid appearing like it's making political choices and to avoid being a target," said Douglas Elliott, a finance expert at the center-left Brookings Institution. "However, I do think present circumstances are ones in which the Fed really does have to do what it believes it has to do for the economy as a whole."
Republicans have criticized the Fed's use of bond buying to stimulate the economy, fearing it eventually will bring inflation. Another round ahead of buying before the election could have the appearance of coming to the aid of President Barack Obama. The president, however, is unlikely to welcome Fed action because it cements a view that the economy is sagging under his stewardship.
"If the economy is bad enough (to warrant action) . how could you possibly interpret that as good news for the sitting president?" Vitner asked.
Sen. Bob Corker, an influential Republican from Tennessee on the banking committee, underscored the political fight in a statement after Bernanke's speech. He warned that "policies from Congress, not more short-term stimulus from the Fed," are needed to restore growth.
Hours later, a top committee Democrat, New York's Charles Schumer, responded in kind.
"It's clear that Chairman Bernanke, as he looks at the economic indicators, believes it's time to prime the pump. He should not let any political backlash deter him from following through and doing the right thing," Schumer said in a statement.
At issue is growth and employment. The Commerce Department on Wednesday revised upward slightly the annualized rate of growth for the U.S. economy to 1.7 percent from April to June, down from the 2.2 percent growth rate from January through March. The jobless rate has been anchored above 8 percent since Obama's first month in office.
It's why the Fed is expected to do something, anything, to support growth. If it waits until the Oct. 23-24 meeting, the decision would come weeks before presidential voting.
"If they are going to make a politically sensitive move, it's probably better to do it in September than October. By the time you get to October, there is an even stronger argument that you could have waited to November," said Elliot.
Bernanke warned Friday that the Fed's monetary policy "cannot achieve by itself what a broader, more balanced set of economic policies might achieve; in particular, it cannot neutralize the fiscal and financial risks that the country faces."
That was a tweak of lawmakers, unable to agree on budget cuts, expiring tax cuts this year and additional measures to spark economic growth.
"Bernanke is 'gravely' concerned about the labor market, thinks cyclical factors are holding it back, and that the potential costs of further easing are outweighed by their potential benefits," Paul Edelstein, director of financial economics for forecaster IHS Global Insight, said in a research note, expecting the Fed to, at minimum, announce it'll hold its lending rates near zero through 2015, extending that by a year from current guidance.