* Charismatic ex-president ignores U.S. objections
* Washington fears "destabilizing" impact on election
* Sunday's vote viewed as key to post-quake stability
By Joseph Guyler Delva and Pascal Fletcher
PORT-AU-PRINCE, March 18 Exiled former Haitian
President Jean-Bertrand Aristide headed back to his country on
Friday after ignoring U.S. opposition to a homecoming some fear
could disrupt Haiti's presidential election runoff on Sunday.
Aristide, 57, who lived in South Africa after his 2004
ouster that he says Washington helped engineer, was flying home
to Port-au-Prince in a charter plane with his family and was
expected to arrive by noon (1700 GMT) on Friday.
He has insisted on returning home just before Sunday's
decisive presidential contest, which the United States and
Western donors want to see produce a stable leadership to steer
Haiti's arduous recovery from a destructive 2010 earthquake.
U.S. officials say the presence of the charismatic, leftist
former Catholic priest, who still has a passionate following in
his poor Caribbean homeland, could be "destabilizing" for the
election, which is being protected by U.N. peacekeepers.
U.S. President Barack Obama called his South African
counterpart, Jacob Zuma, to stress the importance of Aristide
not returning before the poll. South Africa said it could not
stop Aristide from going back to his country.
The vote pits former first lady and law professor Mirlande
Manigat against entertainer and music star Michel Martelly in a
clash of contrasts that has enlivened the first second-round
runoff in the history of Haiti's presidential elections.
Full coverage: [ID:nHAITI]
Factbox on Aristide: [ID:nN17204746]
Factbox on the runoff candidates: [ID:nN17194743]
Despite a generally calm second-round campaign, tensions
and rhetoric have heated up and there are fears Aristide's
potentially divisive presence and large numbers of his
followers in the streets could stir up a volatile electoral
atmosphere in one of the world's poorest states.
"Haiti needs political stability to move ahead with
development efforts," Ambassador Albert Ramdin, assistant
secretary general of the Organization of American States, said
in a statement appealing for calm in the election.
Aides to Aristide say he intends to stay out of politics
and use his expertise in education to assist in Haiti's
recovery from the earthquake, which will require billions of
dollars of foreign donor funds.
Both presidential candidates have said Aristide has the
right as a citizen to return to his country, although they
would have preferred him to come back after Sunday's vote.
Haiti's government said it had drawn up a security plan in
the expectation Aristide's return would generate crowds.
EXPECTED WARM WELCOME
His supporters were preparing to give him a warm welcome,
and banners welcoming "Titide" -- as he is affectionately known
by many Haitians -- have been strung across the streets of the
capital, which still bears the scars of the 2010 earthquake.
"President Aristide is a strong leader who doesn't take
orders from a superpower such as the United States," said
Johnny Mazart, 36, a carpenter. "That's why they ousted him,
because he listened to the Haitian people, not foreigners."
Aristide became Haiti's first freely elected president in
1991, but was overthrown after seven months. Re-elected in
2000, his second term saw economic instability and violence.
Flown into exile aboard a U.S plane after a rebellion
toppled his government in 2004, Aristide has described his
departure as a "kidnapping." His supporters say Washington
worked to keep him in South Africa away from his homeland.
Despite assertions by aides he will stay out of politics,
some believe he may seek to reunite his Fanmi Lavalas party,
Haiti's biggest, which was barred by electoral authorities from
fielding a candidate for the elections on grounds it did not
satisfy registration rules.
Some commentators said Washington's bid to keep Aristide
out of Haiti before Sunday's vote was a mistake.
"Aristide's return marks an end to the era when the United
States gets to choose the political leaders of other countries.
It is a historic victory for democracy and self-determination,"
said Mark Weisbrot, co-director of the Washington-based Center
for Economic and Policy Research.
(Additional reporting by Donald Wilson and Faradjine Alfred;
Editing by Peter Cooney)