O'Donnell would become the second Republican candidate in a race to unseat Democratic U.S. Rep. Sean Patrick Maloney of Cold Spring in November.
O'Donnell, 66, is a retired police commander and Goshen resident who has worked in county government for about 10 years, first in the administration of former County Executive Ed Diana and then as a county legislator.
Maloney has attracted national attention as a leading critic of President Donald Trump and advocate for gay rights.
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