Reports that one of the nation’s largest banks, JPMorgan Chase & Co., lost $2 billion in just six weeks of derivatives trading have reverberated through Washington and on the presidential campaign trail, with Democrats renewing their call for stricter government regulations of Wall Street.

President Obama’s campaign jumped at the chance to use the bank’s loss of billions in customers’ money through the complex, opaque derivative trades to attack his Republican opponent, Mitt Romney, who already committed himself to repealing the tougher regulations Congress imposed on Wall Street following the mortgage crisis from which the nation is still recovering.