Card Check legislation is something clever the unions and Democrats came up with as a way to overrule the secret ballot majority needed in order for a place of business to be required to unionize. The unions call it the Employee Free Choice Act to make it sound like employees have a choice, but there isn't choice when there is no secret ballot. The protection of free choice is dependent on the secret ballot and the unions want that last protection taken away. Workers rights are not the goal of unions--widespread forced unionization is the goal of unions because that means money and power for the unions and for the left.
Texas is a right to work state, which means that no employees are forced to join or financially support a union unless they choose to do so. Teachers are a good example. In Texas, a teacher can decide to belong to none or any of three recognized teachers unions: Texas State Teachers Association (an affiliate of the National Education Association), American Federation of Teachers (an affiliate of the AFL-CIO), or the Texas Federation of Teachers. Union dues vary by the teaching area and the types of insurance, but they are generally not over $200 per year.
On the other hand, consider a state like California, which is not a right to work state. All teachers are required to be members and to pay dues to the California Teachers Union (which is affiliated with the NEA)—there is no choice in California. Union dues are usually around $900 a year depending on where you teach in the state. Employees in non-right to work states must pay an equivalent of dues even if they decide to opt out (which can be a harrowing process and usually is only allowed under strict religious grounds, so it is hardly ever allowed). Forced payments of union dues are used to promote left-leaning politicians and policies.
Right to work states like Texas will be forever changed if Card Check passes. The passing of Card Check will make the distinction of right to work states and forced unionism states a mute point. Get informed at the Alliance for Workers Freedom and contact your representatives.