The chambers of the Iowa Senate.

Democrats already have a 30-to-20 advantage, and in five battleground districts identified earlier this year by The Iowa Independent, Democratic candidates have an overwhelming advantage in cash on hand, with $224,732 compared to $20,071 for the Republicans. Two of those five seats are currently held by retiring Republicans, meaning the Democrats are in good position to expand their majority in the Senate.

Here is a look at fund-raising totals for the five battleground districts, according to the most recent filings with the Iowa Ethics and Campaign Disclosure Board.

District 16

Incumbent Tom Hancock, D-Epworth, narrowly defeated Republican Julie Hosch in 2004, causing some to believe he was ripe for an upset this year. He faces off with Dave McLaughlin, a car dealer from Cascade. Hancock has $16,903 cash on hand compared with $3,125 for McLaughlin.

District 18

The retirement of incumbent Mary Lundby, R-Marion, caused Democrats to immediately put this district on its list for a possible pickup. District demographics lean Republican, but Democratic candidate Rep. Swati Dandekar has a huge cash advantage over her opponent, William Childers, a banker from Marion. Dandekar has $92,941 cash on hand to Childers’ $4,456.

District 22

This is another district where an incumbent Republican is retiring and opening the door to a Democratic pickup. Larry McKibben, R-Marshalltown, is stepping down after three terms. Republican Jarret Heil, a former staffer for U.S. Sen. Charles Grassley and U.S. Rep. Tom Latham, will face off with Democrat Steve Sodders, a Marshall County deputy sheriff from State Center. Sodders has $48,391 cash on hand. Heil has only $8,116.

District 38

Incumbent Tom Rielly, D-Oskaloosa, will face off with Republican Michael Hadley, a fire chief from Richland. Long considered a GOP district, Rielly won in 2004 with the help of a large majority of votes out of Grinnell. He has $54,129 cash on hand compared to $3,536 for Hadley.

District 42

Incumbent Frank Wood, D-Davenport, defeated Republican Brian Sievers by only 480 votes in 2004. This year he will face off with Shawn Hamerlinck, R-Davenport. Wood has a sizable cash advantage, with $12,368 compared to $838 for Hamerlinck.