WASHINGTON — Mitt Romney’s selection of Wisconsin Rep. Paul Ryan as his running mate has become a burning campaign issue in New York’s tight congressional races.

Democrats are trying to link their opponents to Ryan’s plan to overhaul Medicare. And some GOP candidates are distancing themselves from it.

Upstate New Yorkers don’t want to turn Medicare “into a coupon system,” said Julian Shreibman, a former prosecutor running against Rep. Chris Gibson (R-Kinderhook).

But other New York Republicans defended Ryan.

Rep. Ann Marie Buerkle (R-Syracuse), who voted for the Ryan budget, criticized President Obama for slashing Medicare by $500 million to finance health-care reform.

“The blood of Medicare is on the hands of those who voted for the Affordable Care Act,” she said.