President Obama said Friday it was "important" for his administration to declare that gay marriage can be a right that deserves constitutional protection, stepping into a Supreme Court battle that started with California voters and is now shooting for the history books.

The White House Thursday asserted in a key legal brief that the Constitution's equal protection guarantees extend to same-sex couples seeking a California marriage license -- taking a position on the state’s Proposition 8.

Obama told reporters that as his position on gay marriage had evolved, so has the country's -- and that with the Supreme Court taking up the case, "I didn't feel like that was something that this administration could avoid. I felt it was important for us to articulate what I believe and what this administration stands for."

Obama said he believes gay marriage should be available across the country, but sayid his solicitor general, "in his institutional role going before the Supreme Court, is obliged to answer the specific question before them. And the specific question presented before the court right now is whether Prop 8 and the California law is unconstitutional."

"The basic principle is let's treat everybody fairly," Obama said. "Let's treat everybody equally."