Former state Sen. Staci Appel, a Democrat running in Iowa’s competitive 3rd District, raised a whopping $500,000 in the past year, according to a local report.

The huge haul could serve as a deterrent for other Democrats looking to enter the open-seat race. Longtime Rep. Tom Latham, R-Iowa, unexpectedly announced his retirement last month.

House Democrats touted Appel as a top recruit before Latham called it quits.  But in an open-seat contest, national Democratic operatives said this week the door remains open for other Democrats to run here.

Other Democrats, including state Sen. Matt McCoy, are still mulling bids. Christie Vilsack, Iowa’s former first lady who many Democrats had hoped would run here at some point, declined to run. Instead, she has donated and endorsed Appel’s candidacy, according to the Des Moines Register.

Iowa’s 3rd District is a top target for Democrats. Latham is one of 17 Republicans to represent a district President Barack Obama carried in 2012. Obama won it last cycle by a 4-point margin.

On the Republican side, Secretary of State Matt Schultz announced a bid this week, while a number of other Republicans are still deciding whether to enter the race.

Iowa’s 3rd District is rated a Tossup by Rothenberg Political Report/Roll Call.

Correction: 5:43 p.m.

An earlier version of this post misstated the period during which state Sen. Staci Appel raised $500,000. The amount was raised during the past year.