The outcome will affect the committee membership rosters for the upcoming congressional session.
Here's Hillicon Valley’s cheat sheet on the races that matter the most to tech insiders:
Berman vs. Sherman
Redistricting has forced House Democratic Reps. Howard Berman and Brad Sherman into a battle for California’s 30th district seat.
The race has been heated — and almost became physical during a debate last month in which Sherman gave Berman a decidedly unfriendly hug.
A loss for Berman would be a blow to the entertainment lobbies in Washington.
Berman, an influential member of the House Judiciary Committee, has been a trusted advocate for the entertainment industry and pushed for stronger legislation against online piracy, including the Stop Online Piracy Act (SOPA). Sherman also supported the ill-fated anti-piracy bill.
Bono Mack vs. Ruiz
Rep. Mary Bono Mack (R-Calif.) faces a tough challenge on Tuesday against physician Raul Ruiz in California's 36th district.
The race shifted from leaning Republican to a toss-up thanks in part to redistricting, according to The Hill's race ratings.
Bono Mack chairs the House Energy and Commerce Committee’s Commerce, Manufacturing and Trade subcommittee and has been a vocal critic of the Federal Communications Commission and net-neutrality rules. Bono Mack has also pushed for greater online privacy protections, but warned that Congress should not implement strict new regulations on the matter because it could hurt innovation.
Lungren vs. Bera
Rep. Dan Lungren (R-Calif.), the chairman of the House Committee on Homeland Security's Cybersecurity sub-panel, is headed into a rematch battle against his 2010 Democratic opponent, Ami BeraAmi BeraA record number of Indian Americans have been elected to Congress Calif. Dem wins reelection in overtime 115th Congress will be most racially diverse in history MORE.
The Hill's race ratings say the contest is a toss-up due in part to redistricting.
Lungren's cybersecurity know-how has been viewed as an asset to the Homeland Security Committee, although House GOP leadership blocked his cyber bill from moving to the floor this spring after it faced industry pushback. Lungren also initially expressed concern about the effect SOPA would have on the security of the Internet's architecture.
Bass vs. Kuster
Rep. Charlie Bass (R-N.H.), a member of the House Energy and Commerce Committee, is fending off a challenge from his 2010 Democratic opponent, Ann McLane Kuster, an attorney. The Cook Political Report is rating the race for New Hampshire's 2nd district seat as leaning Democratic. Bass, who sits on two key Energy and Commerce sub-panels for tech, spoke out against SOPA on the day Reddit, Wikipedia and other sites blacked out in protest of the bill.
Rep. Jim MathesonJim MathesonNew president, new Congress, new opportunity First black GOP woman in Congress wins reelection Lobbying world MORE (D-Utah), a member of the House Energy and Commerce Committee, will face a tough challenge on Tuesday from one of the GOP's hottest new stars, Mia Love. Matheson hasn't been seen as a major player on tech issues at the E&C panel, but his leaving would open up another Democratic seat on the influential committee. Matheson is the lone Democrat in Utah's congressional delegation and The Hill rates his race as a toss-up.