They need to get him through the Judiciary Committee first.
The US Senate's Judiciary Committee, which Justice Garland will need a majority of to even go before the Senate Floor:
Republicans (11)
•Chuck Grassley, Iowa, Chair
•Orrin Hatch, Utah
•Jeff Sessions, Alabama
•Lindsey Graham, South Carolina
•John Cornyn, Texas
•Mike Lee, Utah
•Ted Cruz, Texas
•Jeff Flake, Arizona
•David Vitter, Louisiana
•David Perdue, Georgia
•Thom Tillis, North Carolina
Democrats (9)
•Patrick Leahy, Vermont, Ranking Member
•Dianne Feinstein, California
•Chuck Schumer, New York
•Dick Durbin, Illinois
•Sheldon Whitehouse, Rhode Island
•Amy Klobuchar, Minnesota
•Al Franken, Minnesota
•Chris Coons, Delaware
•Richard Blumenthal, Connecticut
So we need at least 2 of those Republicans to vote to proceed to the Senate Floor.
Grassley, Graham, Hatch, Flake, and Cornyn are the ones I would work on in that order.