The measure narrowly won passage in the House last week.
Gov. Jack Markell supports the measure, which was introduced barely a year after the state began recognizing same-sex civil unions. It would make Delaware the next state to authorize same-sex marriage.
Under the proposal, no new civil unions would be performed after July 1, and existing civil unions would be converted to marriages.
Supporters say couples in same-sex relationships deserve the same dignity and respect afforded to married couples.
Opponents argue that same-sex marriage redefines and destroys that institution.
The hearing is scheduled for 2:30 p.m. EDT.
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