Sen. Benjamin Cardin has 175 times as much cash as his best-known Republican opponent, as a new survey shows the Maryland Democrat to be in solid shape for reelection.

A Washington Post poll released this week shows that 47 percent of registered voters in the state approve of the job Cardin is doing in the Senate, while 20 percent disapprove and 33 percent have no opinion. Those numbers are nearly identical to Cardin’s scores in a May 2010 Washington Post poll, and are similar to the results of a Gonzales Research & Marketing Strategies survey released two weeks ago.

As has been the case since he was elected to the Senate six years ago, Cardin is not as popular as Sen. Barbara Mikulski (D-Md.), who scored a 67 percent job approval rating in the new Post poll.

But Cardin is still considered the strong favorite to win a second term, particularly given his massive financial advantage. Cardin’s campaign said he had raised close to $700,000 in the last three months of 2011, and he finished the year with more than $2.6 million in the bank.

Ten Republicans have filed to run for the seat, and ex-Secret Service agent Daniel Bongino, the most active candidate in the GOP race, reported raising $61,000 for the quarter, and had just $15,000 in the bank as of Dec. 31. Bongino’s bottom line should be a bit better after a Wednesday night fundraiser hosted by Sen. Mike Lee (R-Utah), who has endorsed Bongino.

Richard Douglas, a former Pentagon official who is also running, said Tuesday that he took in roughly $60,000 in the fourth quarter. Douglas noted that he did not start raising money until Nov. 10, and said he did not have his year-end cash number available yet.

Cardin faces a primary challenge from state Sen. C. Anthony Muse, one of eight Democrats who filed oust the incumbent. As of this posting, Muse’s campaign had not responded to a request for comment on his fundraising.