  A d-wave superconductor, its phase coherence progressively destroyed by
unbinding of vortex-antivortex pairs, suffers an instability related to chiral
symmetry breaking in two-flavor QED$_3$. The chiral manifold exhibits large
degeneracy spanned by physical states acting as inherent ``competitors'' of
d-wave superconductivity. Two of these states are associated with
antiferromagnetic insulator and ``stripe'' phases, known to be stable in the
pseudogap regime of cuprates near half-filling. The theory also predicts
additional, yet unobserved state: a d+ip phase-incoherent superconductor.
