Rep. Tom Kean Jr. (R-NJ) has missed over a month of votes in the U.S. House of Representatives due to an unspecified “personal health matter.” The New Jersey Republican hasn’t cast a ballot in the legislative chamber since March 5.

A representative from Kean’s staff stated in March he was addressing a personal health issue and would return to his regular schedule. However, as April approaches, Kean remains absent from the House floor.

In the closely divided House of Representatives—where Republicans can lose two defections on a single vote and still pass legislation—the influence of each member is critical. This dynamic has repeated throughout this Congress.

For instance, in January, New Jersey Republicans Jeff Van Drew and Chris Smith opposed party leaders on a labor bill, ultimately voting no and sinking the legislation. Speaker Mike Johnson of Louisiana remarked after the incident that his lieutenants had failed to secure passage.

In late January, as Republicans extended a vote beyond its allotted time, Texas Representative Wesley Hunt rushed to Capitol Hill to cast the decisive vote against a bill authorizing military operations in Venezuela. With Hunt’s no vote, the bill failed 215-215.

The activities of rank-and-file members often go unnoticed in the House, which consists of 435 members when fully seated. Kean has missed 37 roll-call votes and will miss additional votes this week.

Kean’s absence is particularly critical for Republicans following the recent special election where progressive Democrat Analilia Mejia won a seat previously held by Democratic New Jersey Governor Mikie Sherrill. The impending swearing-in of Rep.-elect Analilia Mejia (D-Glen Ridge) next week will shift House dynamics: after she takes office, Republicans would hold 218 seats to Democrats’ 214. However, Kean’s indefinite absence effectively reduces that Republican vote by one.

Additionally, Kean represents the 7th district in suburban North and Central Jersey—a politically competitive area where Democrats view him as highly vulnerable in November. Four well-funded candidates are running to challenge him for the nomination.

The House GOP has already faced narrow margins: two recent votes—including a critical resolution ending U.S. involvement in Iran—were decided by one vote each. With Kean’s absence, Republicans risk losing even more ground.