Ebrard, a leading contender to succeed Lopez Obrador, on Tuesday announced that he would step down next week.
Under Lopez Obrador, MORENA in less than five years has replaced the Institutional Revolutionary Party (PRI) as the establishment party.
Lopez Obrador has been urging MORENA to fight for a two-thirds congressional super-majority next year.
Most recent polling gives Mexico City Mayor Claudia Sheinbaum a slight edge over Ebrard in the succession battle, and senior aides to the president have told Reuters they believe she is Lopez Obrador's preferred candidate.
"The most important thing for Lopez Obrador right now is to keep his movement united and alive," Rozental said.
Persons:
Andres Manuel Lopez, Marcelo Ebrard, Lopez, Lopez Obrador, MORENA, Mexico's, Mexico City Mayor Claudia Sheinbaum, Lopez Obrador's, Andres Rozental, Ebrard, Rozental, Sheinbaum, Dave Graham, Mark Porter
Organizations:
MEXICO CITY, Regeneration, Tuesday, Institutional Revolutionary Party, Mexico City Mayor, Reuters, Mexico City, Lopez Obrador, Thomson
Locations:
MEXICO, Mexico City, MORENA, Cohauila, Ebrard, Mexico