Marking a pivotal point in the presidential campaign, the Supreme Court's decision to uphold President Barack Obama's sweeping federal health care law handed the Democratic incumbent crucial election-year vindication for his signature legislative accomplishment.

Republican rival Mitt Romney, an ardent opponent of the law, prepared to use the decision for his own political gain and planned to cast himself as the next best hope for the millions of Americans who favor the law's repeal.

The decision put an end to what had been one of the biggest unknowns in the presidential race. Four months from Election Day, both Obama and Romney will seek to use the high court ruling to bolster their vision for the country, as well as raise money for their campaigns.

The Romney campaign said it had collected more than $100,000 in online donations in the hour after the decision was announced.

Both men were expected to comment around midday Thursday from Washington. Romney was scheduled to speak first, followed by Obama.

The high court announced Thursday, in a 5-4 decision, that it was upholding the requirement at the heart of the health care law: that most individuals must buy health insurance or pay a penalty.