Growing Republican opposition threatened the compromise and Speaker Kevin McCarthy’s political standing as a key committee was poised to move it forward ahead of action on the House floor.
Democrats tried to force a vote to expel Mr. Santos, a Republican of New York who was indicted last week. But Republicans pushed the matter to the House Ethics Committee.
Despite hopes among some Democrats and Republicans that the expiration of strict pandemic-era border rules would force a compromise, bipartisan talks have sputtered.