AUSTIN - In 2004, Sheila Anderson was diagnosed with multiple sclerosis. A year ago, she lost her job -- and the health insurance that went along with it.On Tuesday, the 46-year-old Keller resident was among a busload of Tarrant County residents who traveled to Austin with a message to Gov. Rick Perry and Texas lawmakers -- expand Medicaid to those like Anderson.Several hundred activists from across the state participated in a rally at the Texas Capitol to lend their voices to what has become a highly visible issue in the 2013 Legislature.An expansion of Medicaid under the federal Affordable Care Act would widen coverage to an additional million-plus low-income Texans, but Gov. Rick Perry has repeatedly opposed that option, calling the federal-state insurance program "an unsustainable system."Wearing bright yellow caps emblazoned with "My Medicaid Matters," rally participants marched along Congress Avenue to the south steps of the Capitol, where more than a dozen speakers urged Perry and lawmakers to expand coverage of the joint state-federal insurance program for the poor. House Republicans, in a closed caucus earlier this week, voted overwhelmingly against Medicaid expansion "in its current form" but left the door open to negotiations for what some Republicans describe as a "Texas solution."Anderson and her 66-year-old mother, Martha Anderson, were among about 60 Tarrant County residents who gathered at the St. Andrews United Methodist Church in Fort Worth at about 6 a.m. for the 200-mile bus trip to Austin. The trip was organized by the Allied Communities of Tarrant (ACT), an interfaith non-profit coalition.Anderson said she desperately needs the insurance coverage offered by Medicaid after losing her job at a health facility last year. Grants from a non-profit enable her to buy expensive medication for M.S., she said, but she can't afford to go to a private doctor and has to rely on publicly funded emergency room treatment when a medical emergency arises."I'm quite worried," she said.Dora James of Arlington, a 56-year-old remote operator at a call center, said she works in a job that doesn't offer insurance and doesn't make enough money to purchase adequate coverage for treatment of a blood disorder and high blood pressure."It's rough," she said. "I'm praying that they come around. This would definitely make a difference."Medicaid coverage in Texas is currently limited to the low-income elderly, children, and the disabled and pregnant women. Under the Affordable Care Act, Texas could expand coverage to 1.5 million low-income adults but the U.S. Supreme Court, in upholding the act, held that states aren't obligated to expand their coverage."This is an issue that affects everybody," said ACT coordinator Josephine Lopez-Paul of Fort Worth, who helped organize the Tarrant County trip. "This is our third trip to Austin around this issue and it probably won't be the last."Dave Montgomery is the Star-Telegram's Austin Bureau chief.