Washington (CNN) -- The battle royale for the hearts and minds of voters on President Barack Obama's signature health care reform law kicked into high gear mere moments after the U.S. Supreme Court announced that it had been upheld.
Republicans instantly pounced on the ruling as proof that Obama is trying to raise taxes, while Democrats seemed eager to put the battle behind them and move on.
Millions of dollars have been spent to shape public opinion on the law, and the campaigns and deep-pocketed donors to super PACs will spend millions more. But political experts say the cash poured into messaging may do little to sway voters, many of whom already hold deeply entrenched views on the law.
Instead, the fight for undecided voters may depend heavily on the Democrats' ability to distill a somewhat complicated message into digestible sound bites and Republicans' ability to force-feed a message that the law amounts to a tax increase.
"What we're waiting for in the aftermath of the decision is to see whether the decision legitimizes or makes the health care policy more popular," said Nathan Gonzales, deputy editor of the Rothenberg Political Report. "Right now, it's very polarizing. If health care is the top issue for a voter, they've probably already made their mind up, and the ongoing message war won't change how they feel about it. We have to see for moderate voters if the Supreme Court decision persuades how they feel about it. How the legislation is framed will go a long way into how they feel about it."
Democrats, especially Obama, who was handed a legacy-defining victory by the court, were obviously buoyed by their legal win.
"Essentially, Obama will use the health care decision to brag a bit to the base: 'You see, hope and change mattered. The court decided for us despite the doom and gloom.' It'll make them feel good. I don't think he'll dwell on it because it's unpopular," said University of Virginia political science professor Larry Sabato.
Courtroom triumphs are a far cry from winning in the court of public opinion, and in that regard, Obama has a lot of work to do.
According to a CNN/ORC International poll conducted last month, 51% of Americans oppose the law -- most because they think it goes too far but some because it doesn't go far enough -- while 43% are in favor.
Those findings dovetail with a Pew Research Center poll that asked respondents whether they would be happy or unhappy depending on how the court might rule. It found that 44% of voters said they'd be happy if the entire law were thrown out, and 40% wanted to solely chuck the so-called individual mandate. Just 39% said they'd be happy if the entire law was upheld.
"Of all of the things that are in the (law), the one thing that we know from polling is that the one thing that isn't popular is the individual mandate," said Alan Abramowitz, a political professor at Emory University. "You can talk until you're blue in the face that it's necessary, but it doesn't sink in. For Democrats, the best thing is to play that down."
In his speech Thursday, Obama underscored that the ruling keeps insurance companies from denying coverage based on pre-existing conditions and allows young people to stay on their parents' health insurance, some of the most popular aspects of the law.
"Whatever the politics, today's decision was a victory for people all over this country whose lives will be more secure because of this law and the Supreme Court's decision to uphold it," Obama said.
Republicans have no intention of moving on. Why should they? The Supreme Court's decision that the individual mandate is constitutional under Congress' taxing power but not under the Commerce Clause of the Constitution, as the government originally had argued, hands the GOP the political cudgel it needs to hammer Obama over the head.
Republicans will charge into the fall election yelling "new taxes" as a battle cry.
"That's a message that plays well with the Republican base, playing up the idea that it's going to raise taxes," Abramowitz said. "Republicans are trying to make the argument there's going to be lots of other tax increases. ... It's going to make the whole issue of health care more salient in the fall."
It's also a valuable fundraising tool.
According a Center for Responsive Politics analysis, both campaigns and their surrogates launched an all-out fundraising assault in the hours after the decision.
GOP presidential candidate Mitt Romney's campaign gave regular Twitter updates on the $4.2 million it said it raised online after the decision.
Obama's campaign pointed out that despite the fundraising updates, Romney's campaign hasn't offered an alternative to the health care law.
The Obama campaign, too, bragged about its fundraising total after the decision but wouldn't give out specifics.
"We've outraised the Romney campaign in that time period, but that's not the point," spokesman Ben LaBolt said.
Experts warn against being swayed by the rhetoric over post-ruling fundraising. Several years ago, presidential candidate Rep. Ron Paul, R-Texas, raised more than $6 million in 24 hours during a similar "money bomb."
"$4 million? I'm not that impressed, Ron Paul raised more than that," Abramowitz said. "There's going to be so much spent on both sides it's not going to change much. Each side is going to be spending hundreds of millions of dollars, and they're going to spend the majority of that money in eight to 10 states. The airwaves are going to be completely saturated. ...You get to a point of diminishing returns pretty quickly."