U.S. Republican presidential candidate Mitt Romney gestures while speaking at an election rally in Sterling, Virginia, June 27, 2012.

Credit: Reuters/Jason Reed

WASHINGTON (Reuters) – Republican presidential candidate Mitt Romney raised $4.6 million in the 24 hours following the Supreme Court’s decision to uphold President Barack Obama’s healthcare law.

Romney spokeswoman Andrea Saul said via Twitter on Friday that the former Massachusetts governor had raised the money through 47,000 online donations. “Thanks for everyone’s support for #FullRepeal!” she tweeted, referring to the candidate’s vow to repeal and replace the healthcare law if he is elected president on November 6.

Obama’s campaign said they had also raised a lot of money since the Supreme Court issued its ruling, but officials would not give any figures to back up the assertion.

“It’s perverse that Mitt Romney won’t share details about what he’d do for the millions he’d leave uninsured or at the whims of insurance companies when he ‘kills Obamacare dead,’ but he’ll share the hourly details of his fundraising after the Supreme Court ruling,” said Obama campaign spokesman Ben LaBolt.

“We’ve outraised the Romney campaign in that time period but that’s not the point – our supporters are more committed than ever to ensuring that insurance companies can’t drop coverage for people who get sick or discriminate against people with preexisting conditions by re-electing the president,” LaBolt said.

In May, Romney and Republican groups raised more than $76.8 million for the month from 297,000 donors, an average of about $2.48 million per day and about 9,580 donations per day. So the one-day haul for Romney on Thursday was a bit less than double that amount and the number of donations was about five times the usual number.

The sharp uptick in the number of contributions means Romney is receiving more money in small quantities from regular Americans as opposed to wealthy individuals or organizations donating large sums. This could potentially translate into more votes and repeated donations.

“Research shows small-dollar donors don’t give just once in most cases – they give more than once,” said Republican strategist Matt Mackowiak. “Now Romney’s campaign has a direct link with them. This was about expanding to a much broader network of people who now can become intense, active supporters.”

Most Americans oppose the new healthcare law even though they strongly support much of what it does, according to a Reuters/Ipsos poll released on Sunday. Democrats acknowledge that they have done a poor job of selling the Affordable Care Act and they suffered steep losses in the 2010 congressional elections that followed the law’s passage.

While the court decision avoids an embarrassment for Obama in an election year, it could energize conservative voters who were slow to warm to Romney during a months-long battle for the Republican party nomination.

(Editing by Philip Barbara)