In the First Congressional District, John LaFeria, Kim Letke and Wendy Rosen are vying for the Democratic nomination to face Congressman Andy Harris, who doesn't have opposition in the Republican primary.
By the numbers
Harford's 75 polling places will be open from 7 a.m. to 8 p.m. on primary election day. The county elections board added 10 new locations since the last election in 2010.
As of Wednesday, the county had 152,809 active registered voters, including 61,778 Democrats and 64,957 Republicans. That means both the numbers of Democrats and Republicans dropped from an earlier count, although Republicans continue to hold a lead of several thousand over Democrats.
In last week's early voting in Harford, 1,990 Republicans and 1,256 Democrats participated, according the state board of elections.
The busiest day by far was the final day, Thursday, where 753 votes were cast. The second busiest was the first day, Saturday, March 24, when 544 votes were cast.
There was a huge disparity in early voting by congressional district, perhaps reflecting the location of the single polling place in Bel Air in the heart of the First District. Democrats had hoped to register enough new voters to get a second early voting spot in the Route 40 corridor, which is the Second District, but they fell short.
According to state board of elections figures, 2,661 of the early votes cast in Harford were by people who live in the First District, compared to just 585 early votes from the Second District.
For more information on the primary election in Harford County, go to http://www.harfordvotes.info.
And visit http://www.exploreharford.com for complete election returns and reports on local races throughout Tuesday evening and Wednesday morning.