How to watch Tuesday's primary elections for the 2018 midterms

Today one of the most anticipated days in politics before November's midterm elections. Eight states are holding primaries: Alabama, California, Iowa, Mississippi, Montana, New Jersey, New Mexico and South Dakota.

Poll hours in each state vary but are listed below. CBS News will bring you full coverage of all the primary results as we confirm them. In the meantime, here's everything you need to know about .

How to watch Tuesday's midterm primaries

When are polls open today?

• Alabama: 8 a.m. to 8 p.m.
• California: 10 a.m. to 11 p.m. 
  
• Iowa: 8 a.m. to 10 p.m. 
  
• Mississippi: 8 a.m. to 8 p.m. 
  
• Montana: 9 a.m. to 10 p.m.
  
• New Jersey: 6 a.m. to 8 p.m.
  
• New Mexico: 9 a.m. to 9 p.m.
  
• South Dakota: 8 a.m. to 8 p.m. 
  

*all times Eastern

House of Representatives primary race

Democrats will need to flip 23 seats in Republican-held districts in order to gain control of the House in 2018. CBS News rates 13 of the House districts facing primary elections on Tuesday as "very likely" or "probably" competitive this fall.

States with House candidates on the ballot

• California
• New Jersey
• Iowa

Senate primary race

States with Senate candidates on the ballot:

• California: incumbent Sen. Dianne Feinstein, a Democrat, faces challenge from the state Senate leader Kevin de León;
• Mississippi: incumbent GOP Sen. Roger Wicker is running for re-election, and the nonpartisan special election to replace retiring Sen. Thad Cochran takes place on Nov. 6;
• Montana: Republican voters will determine who will challenge incumbent Sen. Jon Tester;

Gubernatorial primaries

Five of the states having primaries today also have candidates for governor on the ballot.

• Alabama:  Incumbent Republican Governor Kay Ivey is running for a full term in office after filling the vacancy left by the resignation of former Gov. Robert Bentley in 2017;
• California: President Trump endorsed candidate John Cox over GOP challenger state Assemblyman Travis Allen-- the choice could splinter the Republican vote, which might lead to two Democrats on this November's ballot;
• Iowa: Democrats decide who will face off against Republican Gov. Kim Reynolds;
• New Mexico: Democrat Michelle Lujan Grisham aims for the nomination;
• South Dakota: Rep. Kristi Noem goes up against state Attorney General Marty Jackley for the GOP gubernatorial nomination.