WRAPUP 1-Taxes, boos cap brutal week for Romney campaign

* Polls show Obama leading in many battleground states

* Romney offers letter from accountant on 20 years of taxes

* Running mate Ryan faces tough crowd at AARP meeting

WASHINGTON, Sept 21 (Reuters) - Mitt Romney tried to silence

questions about his taxes as the Republican presidential

candidate limped to the end of a brutal week on Friday, while

his running mate faced boos and heckling at a campaign stop.

Slipping poll numbers, fundraising woes and a secretly

recorded video that shows Romney writing off half the electorate

as "victims" have prompted many Republicans to question whether

their candidate is losing a race that had seemed winnable only

weeks ago.

Romney's wife Ann asked Republican critics to cut her

husband some slack and unite to defeat President Barack Obama on

Nov. 6.

"This is hard. You want to try it? Get in the ring,"

Romney's wife, Ann, said on an Iowa radio station late Thursday.

Romney aims to make the election a referendum on Obama's

handling of the sluggish economy, but he has been knocked off

message by a string of missteps over the past week and a half.

New figures show Romney also trailing Obama in fundraising, an

area that was expected to be a strong point of his campaign.

Romney said he was within striking distance of Obama and his

campaign did not need a major reversal of fortunes.

"It doesn't need a turnaround. We've got a campaign which is

tied with an incumbent president," Romney told CBS's 60 Minutes.

With early voting already underway in three states, most

opinion polls have been moving in Obama's direction.

A Reuters/Ipsos daily tracking poll showed Obama stretching

his lead over Romney to 6 percentage points. The Democrat now

leads Romney 48 percent to 42 percent, up 1 point from the day

before.

Other polls show Obama leading in many of the battleground

states that are likely to decide the election. A Wall Street

Journal/NBC poll had Obama leading by eight points in Iowa and

five points each in Colorado and Wisconsin - states that Romney

must carry if he is unable to close the gap in other

battleground states like Virginia and Ohio.

Another poll by Purple Strategies showed Romney leading by

only three percentage points in Arizona, a state that had been

thought to be safely in the Republican column.

"WORST WEEK IN WASHINGTON" - AGAIN

A Washington Post column widely read by political junkies

gave Romney the dubious award of "Worst Week in Washington" for

the second week in a row.

Romney has campaigned on the premise that his success in

business makes him a better bet than Obama to help the country

recover from the deepest recession since the 1930s. The Obama

campaign has attacked the former private equity executive as a

job-killing corporate raider who has little sympathy for the

concerns of average voters.

Seeking to lay to rest Democratic charges that he paid no

taxes in the past, Romney released a letter from his accountants

saying that the lowest annual effective rate he paid was 13.6

percent between 1988 and 2009. Over that period, his average

federal tax rate was 20.2 percent, the accountants said.

That did not satisfy the Obama campaign, which questioned

why he still refuses to release the actual tax returns for those

years.

Romney's vice presidential running mate, meanwhile, was

booed and heckled by members of the retiree group AARP as he

laid out the Republican ticket's case for repealing Obama's

healthcare law and partially privatizing the Medicare health

plan for retirees.

"I had a feeling there would be mixed reactions," Ryan said.

Ryan's dramatic plan to slash spending and overhaul Medicare

have made him a hero to conservatives, but polls indicate that

voters trust Obama more when it comes to protecting the popular

health program.

Romney's 20 point-edge among voters over 65 has eroded over

the past several weeks to the point where the two candidates are

effectively tied, according to Reuters/Ipsos polling data.

Obama was greeted more warmly by AARP members at the New

Orleans event as he told seniors that Romney and Ryan's health

plan would force them to pay more for their medical care.

"I don't consider this approach bold or particularly

courageous. I just think it's a bad idea," he said.

AARP, formerly known as the American Association of Retired

Persons, claims 37 million members and is regarded as one of the

most powerful lobbying forces in Washington.

Ryan traveled to New Orleans to speak to the association,

while Obama addressed them via video from Virginia.

Romney, meanwhile, traveled to Las Vegas to raise money.

The secretly filmed video of Romney, released earlier in the

week, showed him denigrating people who receive government

handouts or pay no federal income taxes - a group that includes

retirees who receive Social Security and Medicare.

"Given the conversations that have been out there in the

political arena lately, I want to emphasize Medicare and Social

Security are not handouts," Obama told the AARP group. "You've

paid into these programs your whole life, you've earned them."