The senators want to know how the program will be changed.
The Florida Republican was elected as part of the Tea Party wave in 2010.
Passage came a day after Pope Francis exhorted Congress on climate change.
Sanders suggested Republicans would become increasingly "out of touch."
McCarthy is seen as the favorite to succeed Speaker John Boehner (R-Ohio).
The top Senate Democrat praised his relationship with the Speaker.
“When some said Republicans could never recover, he never gave up,” the Senate leader said.
He said Boehner "tried to do the right thing under almost impossible circumstances."
House Republicans will huddle to discuss their spending strategy.
The short-term bill includes funding for Planned Parenthood.