DES MOINES - New voter registration numbers show one reason congressional incumbents have little to worry about on Election Day.

The Nov. 1 figures from the Iowa Secretary of State's Office show Democrats with lopsided registration numbers over Republicans in the 1st, 2nd and 3rd congressional districts. In the 5th district, Republicans hold an equally large advantage.

Only in the 4th District are the registration figures competitive, with Democrats holding about an 8,000-person edge over Republicans. Despite that small Democratic advantage in the 4th, Republican Tom Latham represents the district.

But before challengers give up all hope, they can console themselves in the knowledge that plenty of voters don't affiliate with either party. Those independents actually account for more voters than either party in two districts - the 1st in eastern Iowa and 4th in northern and central Iowa.

For Democrats, the biggest cushion is in southeast Iowa's 2nd District, which includes strongholds in Johnson, Lee, Des Moines and Wapello counties. In that district, held by Democratic Rep. Dave Loebsack, Democrats have more than a 60,000-person edge over Republicans.

The figures are reversed in western Iowa's sprawling 5th District, where Republicans lead Democrats by more than 40,000 voters. Four-term Republican Rep. Steve King has cruised to election wins, and in 2008 won in all 32 counties in the district.

Statewide, Democrats had a voter registration advantage of 104,852 over Republicans, but those who didn't declare a party preference made up the biggest percentage. There were 682,641 Democrats, 577,789 Republicans and 704,824 registered without declaring a party.

Besides the advantages offered by voter registration, incumbents also usually raise more money than challengers.

''The standard position of incumbents is they raise a lot of money,'' said Drake University political science professor Dennis Goldford.

Goldford said money gives incumbent a big advantage, but it's not enough on its own to ensure victory.

''Money is necessary, but not sufficient,'' Goldford. ''You use money to scare off opposition.''

The FEC filings filed last month for the period of Jan. 1 through Sept. 30 showed:

- 1st District Democratic Rep. Bruce Braley raised $481,941 and had $46,842 remaining. No Republican raised money.

-2nd District Democratic Rep. Loebsack raised $249,012 and had $278,405 remaining. Republican Christopher Reed raised no money.

-3rd District Democratic Rep. Leonard Boswell raised $413,778 and had $343,215 remaining. Republican David Funk raised $16,477.

-4th District Republican Rep. Latham raised $453,386 and had $419,537 remaining. No Democrats raised money.

-5th District Republican Rep. King raised $271,526 and had $173,833 remaining. Democrat Michael Denklau raised $13,615 during the period and had $13,434 in the bank.

Sen. Charles Grassley will seek re-election in 2010, and the reports showed he had raised $2.06 million, with $4.43 million in the bank.

Prominent Des Moines lawyer Roxanne Conlin - the Democrat's 1982 gubernatorial nominee - said recently she'll likely seek the nomination to oppose Grassley but didn't file a disclosure.

Former state legislators Bob Krause and Tom Fiegen are seeking the Democratic nomination.

Fiegen said he raised $3,781, and had $518 in reserves. Krause said he raised $13,182 and had $3,492 in reserves.