Democratic Sen. Claire McCaskill of Missouri, taking a stance that could inoculate her from GOP attacks as she approaches re-election, is telling the Obama administration she opposes efforts to track drivers' mileage.
In a letter addressed to Transportation Secretary Ray LaHood and provided to The Associated Press on Thursday, McCaskill says any proposal to tax drivers based on miles they drive will place a burden on already cash-strapped motorists.
Her letter comes after Republicans pressed Democrats to disavow the mileage proposal.
A pilot program to track mileage was included in a multiyear transportation funding plan floated earlier this month. The White House has also distanced itself from that plan.
McCaskill is up for re-election in 2012 and considered to be one of the most vulnerable Democrats in the Senate.