An anti-Nelson coalition won enough of the party's 80 state committee seats Tuesday to throw into doubt the controversial Nelson's continuance at the party's helm, according to preliminary results released yesterday.

"I think Nelson will be unseated," predicted Gregory Niblett, coordinator of the Builders' Committee, the anti-Nelson coalition.

Nelson, who has been party chairman for nearly four years, has been accused by his opponents of being too partisan, particularly in his support of conservative Republicans. Indeed, [Francis W. Hatch Jr.] has long held Nelson partially responsible for his 1978 gubernatorial defeat. And they have charged that Nelson has done little to smooth differences within the party.