Why does filibustering persist in the U.S. Senate? This article analyzes senators’ preferences toward majority cloture from 1918 to 1925, a crucial period in Senate history. I find that majority party members were more likely to support stricter cloture rules, but support for cloture reform diminished within both parties for senators far from the party median. I find little evidence that support or opposition to cloture reform was linked to seniority, prior House experience, legislative activism, or state size. These findings are consistent with the micro-level claims of conditional party government theory.