Elena, we hardly know you.

That’s the theme song not only of conservative challengers but of some prominent liberal groups that are ambivalent about Supreme Court nominee Elena Kagan.

 The Washington Post had a fascinating round-up yesterday of groups that might be expected to go all out for Kagan but instead are asking questions. No, it’s not likely that Kagan will be the next Harriet Miers, rejected by those on her side of the aisle. But the tepid support from groups that might be supposed to be her natural allies shows just how little is known about President Obama’s second nominee.

 The National Bar Association, an influential organization representing black lawyers, for example, has withheld backing. The Post notes:

 The group’s president, Mavis T. Thompson, said it “had some qualms” about Kagan’s statements on crack-cocaine sentencing and what it regards as her inadequate emphasis while dean at Harvard Law School on diversifying the school along racial and ethnic lines. Others have expressed reservations about Kagan’s views on affirmative action, racial profiling and immigration.

 The Mexican American Legal Defense and Educational Fund and Lawyers’ Committee for Civil Rights Under Law have also refused to endorse Kagan. The Post reports:

The lingering doubts mean that the White House has not fully tamped down reservations from the left that surfaced immediately after President Obama nominated Kagan in early May. That contrasts with the outpouring of support from the civil rights community — and a central line of objection from conservatives — over Obama’s selection a year ago of now-Justice Sonia Sotomayor, whose strong Latina identity, rather than her judicial philosophy, was a defining aspect of her candidacy.

 Other liberal organizations are in an awkward spot, wary of Kagan but reluctant to criticize the White House explicitly. “We really did struggle with this,” Thompson said of the National Bar Association’s decision to give Kagan the mid-level rating of “qualified” rather than an outright endorsement. “Of course, we want to support President Obama. But . . . I have to make sure I am true to the mission of the National Bar,” whose 44,000 members are predominantly African American.

I’m not sure conservatives should take solace from any of this. It seems highly unlikely that a Justice Kagan will delight conservatives with most of her opinions, though she may well be more unpredictable that Justice Sotomayor.