In a body full of ambitious and egotistical people, Mr. Weiner, 46, stands out for his brash and sometimes even impulsive style. His aggressiveness has served him well, as he has emerged as one of the most visible politicians in New York City and one of his party’s most camera-ready combatants. Liberal cable television seems to love his style, as do many of his constituents.

But he also possesses what friends and associates say is a troubling trait: his tendency to take things just a little too far — whether on the House floor, where he badgered colleagues; on the ice in a hockey game, where he was a relentless trash talker; or in his office, where his demanding managerial style sometimes crossed the line into bullying…

As much as he seems to live for political combat, the congressman also is intensely invested in his recreational pursuits, especially the annual congressional baseball game between Democrats and Republicans. He suits up in a regulation Mets uniform, complete with stirrups, wears his cap backward and is the loudest of trash-talkers in the dugout.