By Steve Holland and Brad Brooks WASHINGTON/UVALDE, Texas (Reuters) – A day after promising residents of Uvalde, Texas, action to address gun violence, U.S. President Joe Biden on Monday sought to appeal to “rational” Republicans to curb high-caliber weapons and take other steps to prevent more mass shootings. “Things have gotten so bad that everybody is getting more rational about it,” Biden, a Democrat, told reporters as he returned from his weekend trip to memorialize the 19 children and two teachers killed last week in the nation’s worst mass school shooting in a decade. “The idea of these…