* Boxer spokeswoman says is senator's "toughest race ever"

* Bad year for Democrats makes Boxer vulnerable

* Republican Carly Fiorina has money, other advantages

By Dan Whitcomb

LOS ANGELES (Reuters) - Of all the U.S. Senate seats
Republicans hope to win from Democrats in November, there may
be few they covet more than that of Barbara Boxer, the powerful
California liberal facing a bruising battle with businesswoman
Carly Fiorina.

But it's not only Republicans who believe that Fiorina, a
multimillionaire former Hewlett-Packard CEO, has a chance to
knock off Boxer. Political analysts are calling the race a
toss-up, and even Boxer's own campaign sees a hard-fought race
in the fall.

"This is clearly Barbara Boxer's toughest race ever,"
Boxer's campaign manager, Rose Kapolczynski, said in an
interview with Reuters. "We're facing an opponent who can write
a virtually unlimited check to her own campaign and voters are
very frustrated with the pace of economic recovery."

"But Barbara Boxer never takes a race for granted and we're
not taking this one for granted either," Kapolczynski said.

Boxer, first elected to the Senate in 1992 after five terms
in the House, appeared formidable in her
first two reelection campaigns -- beating Republican opponents
by 10 points in 1998 and 20 points in 2004.

But current political polls show the Senator with only a
slim lead over Fiorina, a conservative political novice,
despite beginning the campaign with much better name
recognition in what is considered a reliably Democratic state.

Political analysts say that like many Democrats and
incumbent candidates, Boxer 69, faces voter dissatisfaction
over high unemployment and the still-sluggish economy.

Voter surveys have found that the outspoken Boxer, a strong
supporter of President Barack Obama's agenda and a lightning
rod for conservative anger, now has unfavorable ratings of
above 50 percent of Californians.

Based on those factors and others, the nonpartisan Cook
Political Report, which handicaps major U.S. political races,
is among the experts who recently began calling the race a
toss-up -- a shift from earlier positions favoring Boxer.

"Given Fiorina's strengths as a candidate and her ability
to put some personal money into the race, combined with the
national political environment and California's beleaguered
economy that has voters clamoring for change, this contest is
shaping up to be one of the most competitive in the cycle," the
Cook Report said.

FIORINA THE OUTSIDER

Analysts say Boxer's margin of victory in her first two
re-election campaigns may be deceptive because in those cases
she was running in favorable election cycles against opponents
at a clear disadvantage in fund-raising and name recognition.

"This time she's facing a challenging political environment
and an opponent who has a substantial amount of money, and a
woman. This is her first female opponent so that may cut into
her advantage on the gender gap," said John Pitney, a professor
of politics at Claremont McKenna College.

The Fiorina campaign has trumpeted her status as a
Washington outsider and her experience as a self-made Silicon
Valley businesswoman.

As a Democratic incumbent in a Democratic state, "Boxer
should be killing us in the polls right now, and the fact she's
not speaks to the point that we have tremendous enthusiasm on
our side for Carly, and we have a candidate who can actually
work to fix the problems that Boxer spent almost three decades
creating in Washington," Fiorina spokeswoman Andrea Saul said.

"People want the economy back on track and they are looking
for someone with real world experience who has actually created
a job, made a payroll and knows first hand how to get
Californians back to work," Saul said.

But Fiorina, 55, has her vulnerabilities too. She is
running as a conservative in decidedly blue-state California
with two million more registered Democrats than Republicans.

And Boxer's campaign is quick to point out that as head of
Hewlett-Packard, Fiorina laid off thousands of workers and
transferred jobs overseas.

"Voters understand that Wall Street played a significant
role in recession and while Main Street is feeling the recovery
more slowly, Wall Street CEOs are getting bonuses and corporate
profits are on the rise," said Boxer manager Kapolczynski.

'OUT OF STEP'

Fiorina also has staked out positions the Boxer camp
believes are out of step with most Californians.

"Carly Fiorina is out of the mainstream on so many issues
that some voters are going to look at her positions and say, 'I
just can't vote for someone who wants to have more offshore oil
drilling in California, who opposed every job creation bill
since recession started, who wants to make abortion a crime,"
Kapolczynski said.

Raphael Sonenshein, a professor of political science at
California State University at Fullerton, gives Boxer a slight
edge based on the state's Democrat-heavy electorate and because
while Obama's approval ratings are down nationwide, he remains
popular on the West Coast.

"I think it's a tough race but the Boxer people, in a bad
year for Democrats, have reason to be optimistic in
California," Sonenshein said. "What would lose the election for
Boxer would be a real Republican tidal wave and a disengaged
Democratic electorate. Fiorina would be carried by that."

(Editing by Bob Tourtellotte and Sandra Maler))