Battle of addition: 144 days until GOP convention

(CNN) - Your guide to where the race stands for the Republican presidential nomination:

GOP delegate estimate (as of 4/04/2012):
– Mitt Romney: 657
– Rick Santorum: 273
– Newt Gingrich: 137
– Ron Paul: 71
Needed to clinch GOP nomination: 1,144
Access the latest here.

To see where the candidates are campaigning today, see below.

Upcoming contests:

April 24
– Connecticut primary: 28 delegates at stake
– Delaware primary: 17 delegates
– New York primary: 95 delegates at stake
– Pennsylvania primary: 72 delegates at stake
– Rhode Island primary: 19 delegates at stake

On the trail Thursday:
– Romney: Harrisburg and Tunkhannock, Pennsylvania
– Santorum: No public events
– Gingrich: Greenwood, Magnolia and Millsboro Delaware
– Paul: Berkeley, California