This Sept. 14, 2011 file photo shows Sen. Mike Enzi, R-Wyo., at the Capitol in Washington. Enzi is scheduled to explain his proposal Thursday Nov. 17, 2011 that would allow states to require Internet vendors to collect sales tax for all the states regardless of vendor's location. (AP Photo/J. Scott Applewhite, File)

This Sept. 14, 2011 file photo shows Sen. Mike Enzi, R-Wyo., at the Capitol in Washington. Enzi is scheduled to explain his proposal Thursday Nov. 17, 2011 that would allow states to require Internet vendors to collect sales tax for all the states regardless of vendor's location. (AP Photo/J. Scott Applewhite, File)