By the time Kimberly Mata- Rubio sat down in front of Texas lawmakers Tuesday night, 13 hours had passed since she arrived at the Capitol.Mata-Rubio told legislators the wait to testify for a bill that would raise the minimum age to buy certain semi-automatic rifles reminded her of May 24, when hours agonizingly stretched by before she and her husband learned their daughter Lexi was among 19 children and two teachers killed in the worst school shooting in Texas history.Ever since, Mata-Rubio said her mind loops through different scenarios in which her daughter is still alive. What if she had ...