   When President Obama first campaigned for the White House, he
promised to change the tone in Washington, but that tone has
remained pretty nasty. As part of our Parallel Lives series
about the two men running for president, we're exploring the
struggles with their respective legislatures. We heard last week
about Mitt Romney's time as Massachusetts's governor.  Today,
NPR's David Welna reports on President Obama's relationship with
Congress.  DAVID WELNA, BYLINE: On the steps of the U.S.
Capitol, the day he was sworn into office, President Obama
proclaimed a new era of bipartisan cooperation.  PRESIDENT
BARACK OBAMA: What the cynics fail to understand is that the
ground has shifted beneath them; that the stale political
arguments that have consumed us for so long no longer apply.
WELNA: The new president demanded bold and swift action to fix a
battered economy. Eight days later, the Democratic-led House
approved an $825 billion stimulus package without a single
Republican voting for it.  SENATOR OLYMPIA S