Senators will face a crucial test vote Monday that could clear the way for debate on far-reaching legislation to overhaul the nation's financial regulatory system -- or end in a partisan standoff -- as Wall Street once again takes center stage on Capitol Hill. Elsewhere, lawmakers will be preparing to condemn the alleged sins of Wall Street's past and also wrestling over how to prevent such excesses in the future. Top executives from Goldman Sachs, beset by charges that the bank misled its clients by selling them mortgage investments secretly designed to fail, will face questions Tuesday about how the...