WASHINGTON — A Senate showdown has put Goldman Sachs' defense of its conduct in the run-up to the financial crisis on display before indignant lawmakers and a national audience. Democrats hope it also builds momentum for legislation, now before the Senate, to tighten regulation of the nation's financial system.

Goldman Sachs CEO Lloyd Blankfein testily told skeptical senators at a hearing Tuesday that clients who bought subprime mortgage securities from the Wall Street powerhouse in 2006 and 2007 came looking for risk "and that's what they got."

The Senate investigative panel alleges the firm bet against its clients — and the housing market — by taking short positions on mortgage securities, and failed to tell them that the securities it was selling were very high risk.

Blankfein was the final witness in a daylong hearing on Goldman's conduct before the financial near-meltdown that turned into the worst recession since the Great Depression. The Securities and Exchange Commission filed a civil fraud suit earlier this month against the firm and one of its traders.

The Senate Permanent Subcommittee on Investigations has probed Goldman's activities for 18 months.

At the Capitol, Republicans succeeded for a second day in blocking efforts to move toward Senate debate and a vote on the sweeping financial overhaul legislation. At the same time, they floated a partial alternative that they said could lead to an election-year compromise on an issue that commands strong public support. Additional votes are expected later in the week.

Among an array of changes, the legislation would crack down on the kind of lightly regulated housing market investments that helped set off the crisis in 2007.

Both sides are trying to harness voter anger toward Wall Street. Unlike with the health care debate, both Democrats and Republicans say they want tighter regulations passed — but they disagree on timing and significant details.