WASHINGTON, Sept 14 (Reuters) - Republican vice presidential nominee Paul Ryan launched a broad assault on President Barack Obama in a speech to social conservatives on Friday, accusing him of pandering to extremists on abortion and emboldening U.S. enemies in the Middle East.

The Wisconsin congressman told the Values Voters Summit, an annual gathering of religious and conservative activists, that Obama had led a "reckless expansion of federal power" and waged economic class warfare.

Declaring himself "a values voter, too," Ryan mocked Democrats for their convention fight over the mention of God in the platform and questioned claims by Obama that "we're all in this together."

"How hollow it sounds coming from a politician who has never once lifted a hand to defend the most helpless and innocent of all human beings, the child waiting to be born," Ryan said.

"Giving up any further pretense of moderation on this issue, and in complete disregard of millions of pro-life Democrats, President Obama has chosen to pander to the most extreme elements of his party," he said.

He also attacked the requirements under Obama's federal healthcare overhaul that Catholic-affiliated institutions, including hospitals, provide employees with health coverage for contraceptives.

"Never mind your own conscience, they were basically told, from now on you're going to do things the government's way," Ryan said, repeating Republican calls for a repeal of the healthcare law.

Abortion and other social issues largely have taken a backseat so far in a White House campaign focused on the economy but Ryan's speech was an appeal to the Republican's conservative base.

With so few undecided voters left in the race, both parties are trying to fire up their base to turn out to vote on Election Day on Nov. 6.

Republican presidential nominee Mitt Romney, a former head of a private equity firm, has made the struggling economic recovery the centerpiece of his campaign.

Ryan was chosen as Romney's No. 2 in part because of his appeal to conservatives, who have been slow to warm to Romney but favor Ryan for a budget plan that severely slashes government spending and would overhaul Medicare, the retirement plan for seniors.


'BOGUS RHETORIC'

At his Values Voters appearance, Ryan did not focus on the details of his budget but ridiculed Obama's claims that his economic approach was fairer than that of Republicans.

"Here we are, after four years of economic stewardship under these self-proclaimed advocates of the poor, and what do they have to show for it? More people in poverty, and less upward mobility wherever you look," Ryan said.

"After four years of dividing people up with the bogus rhetoric of class warfare, just about every segment of society is worse off."

Ryan also expanded on Romney's recent attacks on Obama's leadership in the Middle East, saying equivocation and mixed signals from the administration had made the region's extremists even bolder.

"Amid all these threats and dangers, what we do not see is steady, consistent American leadership," Ryan said, calling Obama's policy toward Israel "indifference bordering on contempt."

Obama campaign spokesman Danny Kanner said Ryan's speech amounted to "a series of over-the-top, dishonest attacks against the president that once again reminded voters that he's just not ready for prime time."

But many of those in the audience, who cheered Ryan and shouted down protesters who interrupted his speech twice, said they were more enthusiastic about the election with the addition of Ryan to the ticket.

"People were a little worried about Romney because we were uncertain of where he stands," said Jason Handcock, director of Crossroads Pro-Life, an anti-abortion rights group. "But I really like the Romney-Ryan ticket. Paul Ryan is a good conservative."

Ryan defended Romney against charges that he is stiff and aloof, but acknowledged that he and others had told him to talk more about himself.

"Mitt Romney is the type we've all run into in our own communities, the man who's there right away when there's need, but never first in line when praise and credit are being handed out," Ryan said. "He's a modest man with a charitable heart, a doer and a promise-keeper."