WASHINGTON (CNN) -- He has publicly urged Republicans to vote for Sen. Hillary Clinton to keep the divisive Democratic nomination fight alive, but talk radio host Rush Limbaugh said Wednesday he really wants Sen. Barack Obama to be the party's nominee.

Rush Limbaugh urged listeners in states with open primaries to cross party lines and support Hillary Clinton.

"I now believe he would be the weakest of the Democrat nominees," Limbaugh, among the most powerful voices in conservative radio, said on his program. "I now urge the Democrat superdelegates to make your mind up and publicly go for Obama."

"Barack Obama has shown he cannot get the votes Democrats need to win -- blue-collar, working-class people," Limbaugh said. "He can get effete snobs, he can get wealthy academics, he can get the young, and he can get the black vote, but Democrats do not win with that."

But Jamal Simmons, a Democratic strategist and Obama supporter, disagreed, saying the Democratic Party has "the best coalition to go out and talk to people across racial lines, which are the unions."

If Obama wins the nomination, he said, support from unions should help him gain support among blue-collar workers when "they don't have to choose between two Democrats."

Among the Democratic candidates, Clinton has had the advantage with working-class and middle-income voters, though Obama has increased his support in that demographic, according to exit polls.

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In the March 4 Ohio primary, Clinton won voters who made under $50,000 by 14 points. In the April 22 Pennsylvania primary, that advantage was down to 8 points. And in the Indiana primary, exit polls showed the two candidates evenly split among those voters.

For months, Limbaugh urged his listeners in states with open primaries to cross party lines and support Clinton in an effort he has dubbed "Operation Chaos."

The conservative talk show host has said the Republican Party will benefit from a protracted Democratic race that grows more bruising by the week.

It remains unclear how much influence Limbaugh has actually wielded. The Obama campaign estimates 7 percent of Clinton's vote in Indiana could be attributed to crossover Republicans.

According to Indiana exit polls, Clinton did win the Republican vote by 8 percentage points, but those voters made up only 10 percent of the electorate. Watch an analysis of Tuesday's primaries »

Sen. John Kerry -- an Obama supporter -- credited Clinton's win entirely to Limbaugh.

"Rush Limbaugh was tampering with the primary," he said on a conference call with reporters. "If it was not for Republicans taking Democratic ballots, [Obama] would have won."

But CNN senior political analyst Bill Schneider disagrees.

"There is a slightly measurable Rush Limbaugh effect, but it is not the reason she won Indiana," he said. "She dominated the Democratic vote, and two-thirds of the voters were Democratic."

Self-identified Republicans voting in previous Democratic primaries have been more evenly split between Clinton and Obama.

In Ohio, the GOP vote broke evenly, with Clinton and Obama winning 49 percent each. And in Texas, Obama won the Republican vote by 7 points.

On his show Wednesday, Limbaugh declared "Operation Chaos" a success.

"We have done our part to expose Obama through our support of 'Operation Chaos,' effectively using the Clinton campaign as our foil, and Obama and the Democrat Party are the weaker for it," he said. "Every objective has been met and surpassed."

But has Limbaugh successfully advantage the Republicans heading into November? Republican strategist and CNN contributor Rich Galen says yes.

"As this thing grinds down to the last three and a half weeks, I think keeping this going between the two sides may well have some significant impact as we move down toward the fall campaign," he said.

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