We don't have enough information to say what the strategy is yet, but the Republican co-sponsors are all in districts where they are likely to face credible Democratic challengers. Think back to your High School Civics class. In that situation, the way to fend off an issue likely to be raised by a challenger from another party if to propose legislation purporting to deal with the issue that is patently unworkable and is sure to die in Committee. Then, when the Member of Congress goes home, he/she can campaign saying they tried to work on a solution for the issue but they couldn't get the other party to cooperate with them.