With the Democratic race tied to a complex system, Hillary Clinton and Barack Obama are fighting aggressively and publicly over superdelegates.

In a process many believe is undemocratic, DNC superdelegates are not selected based on primaries / caucuses in each U.S. state, but based on their status as current or former elected office holders and party officials.

They are free to choose whoever they like.

“‘Superdelegates’ doesn’t mean that they should leap over the will of the people in a single bound,” joked Sen. Barack Obama’s chief political strategist, David Axelrod, on CBS’ Face the Nation.

Sen. Hillary Clinton’s communications director Howard Wolfson told CBS that the superdelegates “are supposed to vote their conscience.”

Obama leads in the overall delegates and among pledged delegates, assigned based on primary and caucus results. Clinton has more superdelegates in her corner right now, with the overall count still very close.

Neither Hillary Clinton or Barack Obama is expected to have enough pledged delegates to win the nomination outright.

The battle for superdelegates is thus critical, and has spurred interesting debates in places like Massachusetts, where Hillary Clinton won the Super Tuesday primary by double digits, but 10 of 26 superdelegates currently support Obama to nine for Clinton (with seven undecided).

Should Obama backers John Kerry, Ted Kennedy and Gov. Deval Patrick follow the will of the Bay State, or pick who they personally believe is best?

In any case, contests tomorrow in Wisconsin and Hawaii may favor Obama, but the campaigns are looking to March 4, with the delegate-rich Texas primary and Ohio primary at stake (plus Rhode Island and Vermont).

Clinton is aiming for those critical victories that could help her recover in both the delegate count and the fight for momentum.

Meanwhile, Barack Obama quietly met with former Democratic candidate John Edwards at Edwards’ home in Chapel Hill, N.C., Sunday.

Hillary Clinton also met with John Edwards recently. He and New Mexico Gov. Bill Richardson remain coveted endorsements for both contenders.