If money is a predictor of which incumbents are most vulnerable in the 2010 mid-term elections, then analysis from a national nonpartisan group indicates that Iowa won’t see much change.
Researchers at the Sunlight Foundation scrutinized campaign contributions to incumbents and challengers in 2010, 2006 and 1994 — the later years being notable for waves of discontent that swept incumbents out of office and switched political control in Washington, D.C. The group notes that when incumbents raise more than 70 percent of the contributions in their respective races, they rarely lose an election — even during “wave” years.

All data current as of August 4, 2010. (Source: Sunlight Foundation)
Four out of the five members of Iowa’s congressional delegation — two Republicans and two Democrats — have already well exceeded the 70 percent thresholds in their races. The fifth incumbent, Democrat Dave Loebsack in Iowa’s 2nd District, is less than a percentage point away from meeting the threshold and, based on this analysis, appears to be the only of Iowa’s congressional incumbents that is even slightly vulnerable.
Nationally, Democrats have 61 incumbents that have raised less than the 70 percent threshold — compared to 73 for both the majority Republicans in 2006 when control switched to Democrats and Democrats in 1994 when control switched to Republicans.
In 1994, only 3.3 percent of incumbents who exceeded the 70 percent threshold ended up losing their contests. In 2006, that percentage shrunk drastically to 0.08 percent.