The Senate has voted to advance a landmark immigration bill, clearing away the first procedural hurdle in front of legislation that would open the door to citizenship for millions.

The 82-15 vote Tuesday was the first cast by the full Senate on the far-reaching bill that has been a top priority for President Barack Obama.

Hours earlier Obama appeared at the White House to prod Congress to send him a bill by fall.

Despite the lopsided tally on the procedural test, many Republicans made clear that they would require significant changes to the bill to be able to support it on final passage, particularly in the area of border security.

Senate Majority Leader Harry Reid wants to get the bill through the Senate before July 4.

The bill was negotiated by the Senate's "Gang of Eight," four Republicans and four Democrats, including both of Arizona's senators, John McCain and Jeff Flake. Both are Republicans.