Less than 12 hours after the high court's ruling, the GOP nominee's spokeswoman Andrea Saul tweeted that the campaign had received more than $3 million in donations in the wake of the decision.
"Thank you to everyone who donated at http://www.mittromney.com today! Raised $3.2 million online & counting! #FullRepeal," she posted on her Twitter account shortly after 9 p.m., her sixth tweet of the day documenting the Romney team's mounting haul.
Just a few hours after the decision was announced, RedState's Erick Erickson tweeted that he had just donated to Mr. Romney's campaign.
"Swore I wouldn't do it, but I just gave Mitt Romney a donation. Thanks John Roberts. Sigh," he tweeted.
Right after the ruling Thursday morning, Mr. Romney sent a letter to supporters, asking for donations and reiterating his pledge to repeal the law on the first day of his presidency.
"It was always a liberal pipe dream that a 2,700-page, multi-trillion-dollar federal government takeover of our health care system actually could address the very serious problems we face with health care," he wrote. "With Obamacare fully installed, government will reach fully half of the economy — that is the recipe for a struggling economy and declining prosperity."
Earlier in the day before the ruling, the Obama campaign was bracing for a Supreme Court loss. In a letter to donors, Obama campaign manager Jim Messina asked supporters to "have Barack Obama's back" today.
"If you're with him, donate now — before this week's critical fundraising deadline," Mr. Messina said.
An Obama campaign spokeswoman said they do not give out specifics about fundraising except at filing time.