California's two Democratic senators took direct aim at Republican critics of Supreme Court nominee Sonia Sotomayor on Monday, blasting GOP senators who say federal judges should avoid feelings of empathy and instead behave like baseball umpires. Sen. Dianne Feinstein, D-Calif., a Senate Judiciary Committee member, flatly rejected conservative charges that Sotomayor is a liberal judicial activist with a record of discriminating against white men. 'The word activist often is used only to describe opinions of one side,' Feinstein said in her opening remarks at Sotomayor's confirmation hearing. 'I do not believe that Supreme Court justices are merely umpires calling balls and strikes. Rather I believe that they make the decisions of individuals who bring to the court their own experiences and philosophies.' After Monday's hearing, California Democratic Sen. Barbara Boxer, D-Calif., took issue with Republicans like Sen. Jeff Sessions, R-Ala., who declared Monday that 'empathy for one party is always prejudice against another.' Boxer told reporters: 'To say that we don't want empathy -- it makes no sense. Do we want robots at the table? Do they want someone without a heartbeat and a pulse?' In nominating Sotomayor last May, President Obama said that judges should have 'empathy,' a term that Republicans have characterized as code for liberal ideology. Both California senators had kind words for Sotomayor. Boxer called her a 'role model' and 'a wonderful person.' Feinstein praised the 55-year-old New York judge's 'deep and broad experience in the law.' The former San Francisco mayor called Sotomayor 'a very special woman' who has 'overcome adversity and disadvantages' to achieve 'a brilliant legal and judicial career.' Boxer predicted that Sotomayor will win Senate confirmation but cautioned that 'she will be subjected to a lot of tough questions' in coming days. Boxer advised the nominee to 'speak from the heart with the knowledge that you have . . . And, of course, don't let yourself be baited' by Republicans. 