“We expect and welcome suggested improvements to the bill by our colleagues,” Sen. John McCain (R-Ariz.) said at a press conference Thursday. “We will oppose only those amendments that are intended to prevent a comprehensive solution from passing.”

Business groups want to increase the number of visas for immigrant workers while labor unions want to speed up the path to citizenship for an estimated 11 million illegal immigrants.

Democratic and Republican members of the gang, though, pledged unity to fend off attacks on the bill from the right and the left. …

Schumer said he expects additional obstacles.

“Today is just the beginning of our voyage. It will be long and arduous. There will be perils we can’t even anticipate but we start off with optimism because this bipartisan agreement gives us a sturdy ship to ride out the stormy seas ahead,” he said.