CARACAS (AP):

Nicolas Maduro so far has led by imitation, seeking to fill the shoes of a president whose uncanny vigour, mischievous humour and political wiles sowed a revolution and transformed a nation.

As Hugo Chávez did during his 14-year presidency, Maduro has stoked confrontation, and shed tears.

While steering Venezuela through the trauma of Chávez's death, Maduro has pinned his move to the top on his beloved predecessor.

Yet, there are serious doubts, even among diehard Chávistas, about his ability to lead the nation.

At his swearing-in last Friday evening as acting president in the National Assembly chamber where less than a decade ago he was just another lawmaker, Maduro pledged his "most absolute loyalty" to Chávez.

Then he launched into another fiery, lionisation-of-the-masses speech punctuated by tears, Chávez-style harangues and attacks on capitalist elites and the international press.

"This sash belongs to Hugo Chávez," he said, choked up, after assembly speaker Diosdado Cabello slid the presidential band over his head. Hours earlier at Chávez's funeral, Maduro delivered a speech similarly strident in content and tone.

Pesidential successor

Maduro, 50, hasn't stopped idolising the outsized leader who made him Venezuela's foreign minister, then vice-president and, before going to Cuba for a final cancer surgery in December, publicly selected him as the presidential successor.

Filling the leadership void since Chávez disappeared from public view after his surgery, Maduro has verbally sowed conflict and polarisation.

But many Venezuelans find him bland and uninspiring. Some blame his lack of education, noting the former bus driver never went to college.

Others say it goes much further. After all, Brazil's hugely popular former president, Luiz Inacio Lula da Silva, also started out as a union leader.

"Nicolas Maduro does not embody Chávismo. He's not in touch with the people," said Carlos Borrola, a 57-year-old member of a "colectivo," a radical pro-Chávez citizens' militia.

As Chávez's political heir, he had three months to establish himself as the face of Chávismo.

It fell to him to announce Chávez's death, and he sweated through the hours-long walk last Wednesday as the funeral cortège crawled through adoring crowds, some shouting "with Chávez and Maduro, the people are secure".

Boycotted ceremony

When Maduro was sworn in, boisterous lawmakers shouted: "Chávez lives, Maduro carries on." The ceremony was mostly boycotted by the opposition, which called it illegitimate because Venezuela's constitution says the assembly speaker should be interim president.

For the socialist Chávista movement, Maduro's leftist credentials are unassailable.

Chávez named him vice-president after defeating opposition leader Henrique Capriles in the October 7, 2012 election.

Once Chávez fell from sight as his health failed, Maduro began wielding the huge state media machine built by his mentor as campaign tool, with a view to the possibility of a special presidential election.

He began to criss-cross the nation and show up on state TV presiding over the distribution of apartments and buses for university students.

As Chávez's death drew nearer, the "political marketing" and incendiary rhetoric of Maduro stepped up while criminal investigations of opposition leaders for alleged financial irregularities were launched.

Maduro expelled two US military attachés as alleged spies just hours before he announced Chávez's death last Tuesday, surprising analysts who had thought a rapprochement between the two nations might be possible under the new leader.