WASHINGTON - The Senate has voted to start debating immigration, including whether to protect hundreds of thousands of young immigrants in the U.S. illegally.

Monday's vote was 97-1. The overwhelming margin belies how hard it will be for any measure to actually pass.

Many Republicans back President Donald Trump's plan offering possible citizenship to up to 1.8 million young "Dreamers." He's also seeking $25 billion for security, including his proposed border wall, and would limit the relatives legal immigrants can bring to the U.S.

Democrats want citizenship for Dreamers but are unwilling to clamp down on legal immigration.

Any measure will need 60 votes — meaning significant bipartisan support.

Senators are working on amendments behind the scenes. It is unclear which will be voted on and what can pass.