President Barack Obama's Supreme Court nominee faced tough Senate questioning Tuesday, especially from Republicans who want to portray her as inexperienced and too politically liberal to fairly interpret the US Constitution.Barring unexpected missteps, however, Elena Kagan was expected to win approval of the Democrat-dominated Judiciary Committee and then the full Senate before the top US court opens its next session later this year. RELATED:Kagan attacked for idolizing Judge BarakRiskin: Kagan showed great wisdom in her youthQuestioning during the hearing, expected to last until late this week, likely will be particularly detailed because Kagan has never served as a judge and, therefore, has left behind no body of written decisions to reflect her interpretation of the law.Kagan sits before senators a second time, having already been confirmed as Obama's solicitor general, the chief administration lawyer who argues cases before the Supreme Court. She now is defending her qualifications to sit on the nine-member court to replace Justice John Paul Stevens, a liberal stalwart who has retired.Ideological divisions: Republicans ready to argueThe hearing began Monday with ideological divisions quickly displayed in senators' opening statements. Sen. Patrick Leahy, the committee chairman, called Kagan's views "well within the legal mainstream."He cautioned his colleagues against trying "to impose an ideological litmus test to secure promises of specific outcomes in cases coming before the Supreme Court."Sen. Jeff Sessions, the ranking Republican, countered that her "career has been consumed more by politics than law.""It's not a coronation but a confirmation process," said Sessions.The Republican lines of attack were well developed as the hearing began.Sessions said Kagan had "less real legal experience of any nominee in at least 50 years." He said her decision to bar military recruiters from Harvard Law School's career services office violated the law — a legal conclusion disputed by the White House.Several Republicans also expressed concerns Kagan would become a judicial activist like Justice Thurgood Marshall. Kagan frequently refers to the legal standards of that liberal icon for whom she served as a Supreme Court clerk in the late 1980s.Democrats said they too would focus on judicial activism but of the conservative variety. Several Democratic senators complained that Supreme Court Chief Justice John Roberts, nominated by former President George W. Bush, has pushed an ultraconservative interpretation of America's founding law.Kagan's opening statementIn her opening statement, Kagan was a model of restraint, choosing her words with great care and telling the panel she would approach all cases with "evenhandedness and impartiality." The nominee insisted she would be properly deferential to Congress while safeguarding individuals' rights.Kagan billed herself as a consensus-builder for the ideologically polarized court and said she would emulate retiring Justice Stevens by "listening to each party with a mind as open as his ... to render impartial justice."Even so, Republicans were set to question Kagan on controversial issues from gun owners' rights to abortion to campaign finance, arguing that she'd bring liberal politics and an antimilitary bias to the job of a justice.Kagan, who would be only the fourth woman to ever serve on the court, would not likely change the ideological makeup of the divided court, since she would replace the liberal Stevens. But she would add relative youth to the liberal wing of the court, which became more conservative under Bush.Kagan brings a stellar legal resume to the job, with the exception of never having served as a judge. Her background includes education at Princeton, Oxford and Harvard, clerked under Marshall, worked in private practice, taught at and became the first woman dean at Harvard Law School and served in the White House under former President Bill Clinton.