Minnesota Sen. Amy Klobuchar has padded an already commanding head start in the 2012 campaign money chase, ending September with $4 million in her fundraising account.
The first-term Democrat raised about $1 million in the previous three months.
So far, she has two announced Republican opponents: former state Rep. Dan Severson and suburban city council member Joe Arwood.
Neither has reported raising significant dollars toward the campaign.
Since winning the seat in 2006, Klobuchar has raised about $5 million - more than half of the nearly $9 million she spent the last time she ran.