Nebraska Attorney General Jon Bruning remained far out front Wednesday in the 2012 Republican Senate fundraising derby, but state Treasurer Don Stenberg has scored a significant breakthrough.

Bruning's year-end campaign finance report showed he raised more than $400,000 during the fourth quarter of 2011 and entered the new year with nearly $1.7 million in cash on hand.

Stenberg reported $252,000 in contributions during the fourth quarter, and his filing with the Federal Election Commission showed about $177,000 in cash on hand.

Stenberg is benefiting from a huge assist by the Senate Conservatives Fund, a political action committee chaired by Sen. Jim DeMint of South Carolina.

The PAC website shows more than $521,000 raised for Stenberg's campaign. The committee purchased $210,000 in 30-second TV advertising in Nebraska this month to support him.

DeMint's support has helped address the fund-raising challenges that have hampered Stenberg's earlier campaigns, including a 2006 bid for the Republican Senate nomination.

"Our financial donors have told me they want a senator who is committed to public service, not someone who sees public office as a ticket to personal financial gain," Stenberg said.

In a statement accompanying release of his report, Bruning said, "Nebraska families want a senator who will fight to cut spending, balance the budget and repeal Obamacare."

Meanwhile, Bruning campaign manager Trent Fellers repeated Bruning's decision to wait to schedule campaign debates until the GOP field is settled with the March 1 filing deadline.

The other four candidates who already have filed for the Republican nomination have agreed to a debate in Kearney on Feb. 11.

Stenberg, state Sen. Deb Fischer of Valentine, Pat Flynn of Schuyler and Spencer Zimmerman of Omaha accepted debate invitations from the Republican Liberty Caucus.