Washington, Mar 29 (IANS): The fate of President Barack Obama's signature federal healthcare overhaul hangs in balance with the US Supreme Court wrapping up a historic hearing with an apparent ideological divide among conservative and liberal judges.

In six hours of hearings spread over three days, the Supreme Court heard arguments on one of the most controversial issues of the day, touching on legal concepts involving federal and state powers, individual rights and legislative intent.

As many as 26 opposition Republican ruled states have challenged Obama's signature legislation that requires most Americans to have health coverage as part of a systemic overhaul intended to lower costs as he seeks re-election in November.

On the final day of hearing on legal challenges to the 2010 Affordable Care Act Wednesday, the nine justices tackled the question of what would happen if they ruled that the heart of the law, the individual mandate that requires people to get health coverage or pay a fine, was unconstitutional.

The Supreme Court ruling is expected in late June in the thick of the election campaign. An adverse judgement would be a setback for Obama, but White House spokesperson Josh Earnest said the Obama administration remained confident the healthcare law is constitutional.

Anyone who tries to predict the outcome of the case based on the questions justices asked during this week's arguments "is not a very good student of the Supreme Court", Earnest told reporters.

Justice Department lawyers faced similar tough questions from conservative judges in lower courts that later upheld the law "in at least a couple of these cases", he said.

However, some of the attorneys general of states opposing the healthcare law said the three days of arguments showed the justices had serious concerns about the law.