(CNN) As Sen. Cory Booker nears a public decision on whether he will run for president in 2020, the machinery of his would-be campaign is shifting into a new gear: ready for launch.

Several potential Democratic candidates are expected to announce their candidacy in the early half of this year, and Booker's allies are now working to put the final pieces in place to ensure that, when he gives the signal, a campaign framework would be ready and waiting.

The campaign would likely be based out of Newark, where Booker served as mayor, a source familiar with his thinking tells CNN. The campaign would be centered on the message of unity and love -- themes Booker has made a central part of his political profile.

The New Jersey senator and his chief of staff, Matt Klapper, have narrowed their search for a campaign manager following months of interviews, a source familiar with the discussions told CNN. Among the leading candidates is Addisu Demissie, who oversaw Booker's 2013 Senate bid and most recently steered California Gov. Gavin Newsom's campaign. Demissie was formerly national political director for President Barack Obama's OFA.

Klapper, who has worked with Booker for nearly two decades, dating back to the Newark City Council, is also widely expected to take on a senior role in the would-be campaign.

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