Sen. Barack Obama (D-Ill.) added his name to legislation overhauling the public financing of presidential elections this week, earning him plaudits from watchdog groups. For now, the senator himself has opted to forgo public funding in his own 2008 campaign.

Democracy 21 President Fred Wertheimer yesterday urged Obama’s presidential rivals to follow his lead and cosponsor this session’s bill from Sen. Russ Feingold (D-Wis.). It would raise significantly the spending cap for candidates accepting public funds during their White House campaigns in an effort to keep the system relevant.

“Senator Obama has provided important national leadership by becoming the first presidential candidate to sponsor vitally needed reform legislation to protect the integrity of the presidency and to join in the battle for its passage,” Wertheimer said.

Feingold’s and Obama’s bill would take effect in the 2012 presidential cycle. At the moment, Obama is awaiting a response from the Federal Election Commission to his request for a unique fundraising arrangement: eschewing public money for the primaries, but reserving the right to return already-raised donations and take public funds for the general election, if he wins the Democrats’ 2008 nod.