The margin of Neito's victory falls short of a mandate for the PRI. (Courtesy Creative Commons/ AlfaroGalan)

Nieto claimed victory for the PRI (Institutional Revolutionary Party) Sunday night. In a campaign that was dominated by Mexico's deadly drug war and lagging economy, Nieto ran on a platform that promised to curb rising food prices, promote energy reform and quell the rising violence.

"In the Mexico we want, there is no room for corruption, for cover-ups and least of all for impunity," Nieto said recently. "It's time to break with the past."

Nearly half of Mexico's population lives in poverty. Unemployment is relatively low at 4.5 percent but a huge gap persists between the rich and poor.

Nieto fashioned himself as the new face of the PRI to revive a scandalous party image. The PRI ruled Mexico for 70 years before losing power in 2000. Married to a glamorous soap star, Angelica Rivera, Nieto's image is a break with the party's corrupt history, which includes vote-rigging and ties to organized crime.

According to CNBC:

More nagging have been accusations that Pena Nieto failed to do enough to tackle high murder rates of women in the State of Mexico.

And most persistent of all are the allegations that he is too close to the PRI's old ruling elite, who critics say too often saw public service as a means of private enrichment.

While Nieto is leading in votes, analysts point out the few-point lead is far from a resounding welcome for the new ruling party. From CBS:

It was not the mandate the party had anticipated from pre-election polls that had at times shown the youthful, 45-year-old with support of more than half of Mexico's voters.

Instead, he won 38 percent support, about 7 points more than his nearest rival, according to a representative count of the ballots, and he went to work immediately to win over the two-thirds who didn't vote for him, many of whom rejected his claim that he represented a reformed and repentant party.

Even with the presidency decided, many, like David Rees from Capital Economics, are holding their breath to find out the results of Mexico's congressional elections.

"The outcome of the congressional elections will be crucial. Those official results are not expected until Wednesday," Rees told Reuters. "But the early signs are that the coalition of the PRI and the Green Party will fall short of securing a majority in Congress."

Without a majority in Congress, Rees worried political concessions would water-down reforms and continue ongoing political deadlock.

Outgoing President Felipe Calderon called to offer his congratulations to the president-elect. But Neito's nearest rival, Andres Manuel Lopez Obrador, has yet to concede.

Nieto will be inaugurated into office in December.

[View the story "Reaction to the election is mixed:" on Storify]

Follow Neon Tommy's coverage of the Mexican elections.

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