WASHINGTON — Just as President Barack Obama is pushing new initiatives on gun control and immigration, the gloomy old problem of a sluggish economy is elbowing its way back into prominence. Consumer confidence is falling, the economy is contracting and large automatic spending cuts are threatening to hit the Pentagon and other programs, with uncertain consequences.

These troubles arise as Obama's public approval is improving and as he begins to use his sway to promote the key features of his second-term agenda. The White House, the Federal Reserve and independent economists attributed the shrinkage in gross domestic product and the drop in consumer confidence to one-time events and said underlying economic factors were still showing encouraging signs.

But in politics, power resides in the moment. Any immediate economic setback — or the perception of one — could weaken Obama's clout or at least distract him as he carefully tries to put his imprint on initiatives dealing with immigration and gun violence.