By David Lindsey
CHARLOTTE, North Carolina (Reuters) - In the two years since President Barack Obama signed the Affordable Care Act, he and his fellow Democrats have largely struggled to articulate the merits of the complex law.
The law - which requires most people to buy health insurance - bans insurers from denying coverage to children with pre-existing medical conditions. It eliminates lifetime caps on essential benefits, allows young adults to stay on their parents' insurance until age 26, and can make prescriptions less expensive for people on Medicare, the nation's health insurance program for those 65 and older.
Even so, Republicans have been able to sway public opinion against the law, in part by casting it as a "job killer" that stifles hiring by raising costs to employers.
But at their convention this week in Charlotte, Democrats showed signs of grasping an effective strategy to sell the healthcare law that Romney has vowed to repeal if he is elected November 6.
Tuesday's session featured emotional testimonials for "Obamacare," including one from Stacy Lihn, a mother who said the law will allow her family to afford caring for their young daughter, Zoe, who was born with a congenital heart defect.
"Romney repealing healthcare reform is something we worry about literally every day," Lihn said. "Zoe's third open-heart surgery will happen either next year or the year after. If Mitt Romney becomes president and Obamacare is repealed, there's a good chance she'll hit her lifetime cap."
The tears on delegates' faces made it clear: Democrats had found a simple and touching way to cut through the density of Obama's signature legislative achievement.
"Expect to see more (Obamacare testimonials) this fall," one Democratic strategist said.
Here's a look at some other key themes to emerge during the Democratic National Convention:
**When it comes to 2016, Democrats have a bench, too.
In Tampa last week, Republicans rolled out a new generation of potential contenders for president in 2016.
They included Florida Senator Marco Rubio, 41, and Wisconsin Congressman Paul Ryan, 42, who is Romney's vice presidential running mate but could be in play for 2016 if Romney loses in November.
This week in Charlotte, a few Democrats rose to the moment.
San Antonio Mayor Julian Castro, 37, Massachusetts Governor Deval Patrick, 56, and Newark (New Jersey) Mayor Corey Booker, 43, delivered stirring convention speeches - and signaled that part of Obama's legacy could be helping to position other minorities to make runs at national office.
Booker neatly summarized the anger that many Democrats feel toward Republicans who portray efforts to make the nation's wealthiest citizens pay more in taxes as "class warfare."
"Being asked to pay your fair share isn't class warfare," Booker said. "It's patriotism."
**How different is 2012? Republicans are talking less about foreign policy, and Democrats are organized.
At the Republican convention that Romney's team put together in Tampa, Florida, last week, the primary focus was bashing Obama's stewardship of the weak economy.
Less prominent - aside from a much-praised speech by former Secretary of State Condoleezza Rice - was foreign policy.
It's traditionally a Republican priority, but isn't getting as much attention this year, partly because Romney and Ryan have little foreign policy experience and any debate on the subject inevitably leads to Obama's success in overseeing the demise of Osama bin Laden.
In Charlotte, Democrats bucked a tradition of their own.
Democratic conventions often have been raucous, disorganized affairs, complicated by various special interests grappling for power in the large, diverse party.
This year, it appeared most everyone was on the same page.
The convention featured memorable speeches (particularly by former president Bill Clinton, President Obama and first lady Michelle Obama), and tightly choreographed messaging on themes such as helping the middle class, abortion rights and support for Obama's healthcare overhaul.
Divisions remain: Some Democratic activists say the party, in its focus on the middle class, is not devoting enough attention to the needs of lower-income families.
And there was the divide over the party's platform that led to an embarrassing re-vote on the document to insert a mention of God and language recognizing Jerusalem as Israel's capital.
The vote took place after Obama expressed his dissatisfaction that the approved platform had omitted both, and as Republicans began to air commercials criticizing the Democratic platform.
Through the years, U.S. presidents have expressed support for making Jerusalem the capital of Israel, but have not moved the U.S. Embassy from Tel Aviv because of a belief that the future of Jerusalem should be decided through talks between Israelis and Palestinians.
Even so, declaring Jerusalem the capital is a signal of support for the most important U.S. ally in the Middle East, and is a nod to the influential Jewish-American community.
**Bill Clinton isn't going away.
In his speech Wednesday night, the former president showed why many people consider him the most talented politician of his generation.
His folksy, methodical breakdown of the Democratic positions on healthcare, Medicare, taxes and other issues also showed why he could be valuable surrogate for Obama in the next two months.
Hours after Clinton's speech, Obama's team said the former president would campaign for Obama next week in Ohio and Florida, politically divided states that are likely to be crucial to the outcome of the November 6 election.
So could Clinton's re-emergence in presidential politics pave the way for his wife, Secretary of State Hillary Rodham Clinton, to get back in the game and run for president in 2016, eight years after losing the Democratic nomination to Obama?
It's safe to say that a good number of loyal Democrats in Charlotte this week hope so. Former U.S. House of Representatives speaker Nancy Pelosi is publicly rooting for Hillary Clinton to run again.
Mrs. Clinton will be 69 on Election Day in 2016 - the same age that Republican Ronald Reagan was when he took office in 1981. She is retiring from the State Department post after the November election.
But whether Obama - the nation's first African-American president - wins or loses in November, the former first lady will hear calls from Democrats to help her party make history again.
(Editing by Doina Chiacu)