Washington — Hillary Rodham Clinton was hours away from announcing her much-anticipated second presidential campaign on Sunday, preparing to debut a message that will focus on strengthening economic security for the middle class and expanding opportunities for working families.

The former first lady, U.S. senator and secretary of state planned to enter the 2016 Democratic race with an online video posted on social media, to be followed in the days ahead with small events with voters in early-voting states.

Campaign officials said she would seek the White House as a results-oriented "tenacious fighter."

The opening strategy was described ahead of the announcement by two senior advisers who requested anonymity to discuss her plans.

Clinton's strategy has parallels to the approach President Barack Obama took in 2012. He framed his re-election as a choice between Democrats focused on the middle class and Republicans who sought to protect the wealthy and return to policies that led the country into recession.

Republicans pounced even before Clinton's announcement.

Republican National Committee chairman Reince Priebus has outlined plans for a broad effort to try to undermine Clinton's record as secretary of state while tying her to Obama's most unpopular policies.

Early Sunday, potential GOP rivals Jeb Bush and Rand Paul previewed their case against Clinton.

"We must do better than the Obama-Clinton foreign policy that has damaged relationships with our allies and emboldened our enemies," Bush, a former Florida governor, said in a video.

Paul, a Kentucky senator who launched his presidential campaign last week, pointed to the Clinton family's foundation, saying it was hypocritical for the Clintons to accept money from Saudi Arabia, which places public restrictions on female movement and activity.

"I would expect Hillary Clinton if she believes in women's rights, she should be calling for a boycott of Saudi Arabia," Paul said on NBC's "Meet the Press." ''Instead, she's accepting tens of millions of dollars."

Clinton intends to sell herself as being able to work with Congress, businesses and world leaders, the advisers said Saturday. That approach could be perceived as a critique of Obama, who has largely been unable to fulfill his pledge to end Washington's intense partisanship and found much of his presidency stymied by gridlock with Congress.

Clinton was not expected to roll out detailed policy positions in the first weeks of her campaign. Advisers said she planned to talk about ways families can increase take-home pay, the importance of expanding early childhood education and making higher education more affordable.

It's not clear whether that would include a noticeable break with Obama on economic policy. The GOP has hammered Obama's approach as anti-business and insufficient in the wake of the recession. The White House says the economy has improved significantly in recent years.

The unemployment rate fell to 5.5 percent in March, but manufacturing and new home construction slowed, cheaper gas has yet to ignite consumer spending and participation in the labor force remains sluggish.

Clinton is seen as the overwhelming favorite for her party's nomination. Still, her team has said her early strategy is designed to avoid appearing to take that nomination for granted.

The early events were expected to include discussions at colleges, day care centers and private homes, and stops at coffee shops and diners. After about a month of such events, Clinton planned to give more specifics about her rationale for running.

Clinton's husband, Bill, and daughter, Chelsea, are unlikely to appear at her early events.

Bill Clinton, the former two-term president, said recently that he wanted to play a role as a "backstage adviser" in his wife's campaign. Advisers said Bill Clinton has been engaged with his wife in some of the policy discussions leading up to this weekend's rollout.

To prepare for the campaign, Clinton has spent months meeting with economic policy experts. Clinton's growing team of staffers began working Friday out of a new campaign headquarters in Brooklyn. They gathered Saturday to hear from campaign manager-in-waiting Robby Mook, who told them the campaign would value teamwork, respect, diversity, discipline and humility.

A Democratic official in attendance described the meeting on condition of anonymity because it was a private strategy session.