Florida U.S. Senator Marco Rubio said yesterday he will vote against the GOP’s tax package unless negotiators expand the child tax credit. Rubio wants to increase the basic $2,000-per-child tax credit that would go to low-income families. In the current bill, families that pay little or no income tax would get only $1,100 per child. Rubio wants that amount increased, but he did not specify an amount. The Senate passed its earlier version of the tax package by only 51-49, with Rubio voting for it. His defection makes passage of the bill increasingly problematic.