SUN LAKES, Ariz. — It was no accident that Gina Gennaro found herself outnumbered at a town-hall-style meeting the other night and shushed when she tried to press her objections to Republican plans to remake Medicare.

Throughout the two-week Congressional recess that ended Monday, at public meetings across the country, a running skirmish was fought among grass-roots activists from both parties. They wanted to duplicate — or prevent — the kind of angry confrontations, many of them organized by Tea Party supporters, that occurred at such meetings during the heat of the 2009 debate over the health care overhaul.

This time, the focus was on budget cutting. Who won the skirmishes depended on which side filled the most chairs. And supporters of both parties were taking part in the maneuvering.

“We need you to show up in force to make sure the far left doesn’t drown out the debate!” Tea Party activists said in an e-mail alert intended to fill as many seats as possible at a gathering that Representative David Schweikert, a freshman Republican from the Phoenix area, held Wednesday night in a police substation in Tempe.