CUCUTA, Colombia Since he first stood on a stage Jan. 23 and announced he was seizing the presidency from Nicolas Maduro, Juan Guaido, the 35-year-old head of Venezuela's Congress, has embodied hope for change. With the backing of the U.S. and more than 50 other nations and the adoration of millions he made the country believe his slogan "vamos bien" we're doing well.

But last week's failed military uprising and a spate of violent but fruitless demonstrations have some wondering if Guaido, and the opposition at large, have what it takes to oust Maduro and end 20 years of single-party rule. Suddenly "vamos bien" is becoming harder for some to utter.

A poll released Monday by Caracas-based Meganalisis found that Guaido's approval ratings dropped to 50 percent, down from 84 percent in January. He's still far more popular than Maduro whose approval rating is at 4 percent but the precipitous drop can't be ignored, said Meganalisis Vice President Ruben Chirino Leanez.

"The opposition has to be worried because they haven't been able to deliver solutions to the people," he said. In the wake of last week's failed military uprising, Guaido called for more street protests and a general strike well-worn tactics from years past. "It's craziness to think that if you keep doing the same things you will get different results."

April 30 was a watershed for Guaido. That morning, surrounded by a dozen or so armed soldiers, he declared that the country was in the final phases of "Operation Liberty" a fuzzily defined push that many believed would sweep Maduro out of office. By his side was his political mentor and one of the country's most polarizing figures, Leopoldo Lopez, who was sprung from house arrest under the scheme.

In retrospect, the image of Guaido, the so-called bridge-builder, beside Lopez, considered a political bomb-thrower, wasn't a good look, said Jesus Seguias the head of the DatinCorp, a Venezuela-based political analysis firm.