It’s Primary Day in Illinois — not just for Republican presidential candidates, but also for several lawmakers.

Rep. Adam Kinzinger (R-Ill.) faces a closely-watched primary battle. (The Hill/Benjamin J. Myers)

“Democrats have a great shot at picking up four seats from Republicans under a new redistricting map drawn by the Democratic legislature, but they will also have to defend the seat of retiring Rep. Jerry Costello (D),” Blake notes at The Fix. “In all, as many as six Illinois congressional seats could be competitive come November.”

Three lawmakers — Reps. Adam Kinzinger (R-Ill.), Don Manzullo (R-Ill.) and Jesse Jackson Jr. (D-Ill.) — are in primaries Tuesday, with Kinzinger and Manzullo battling for the nomination to represent the state’s 16th District and Jackson facing off against former Rep. Debbie Halvorson. (Read Paul Kane’s authoritative tale of the Kinzinger-Manzullo matchup here.)

Another race to watch: Will liberal darling and former Obama administration official Tammy Duckworth beat Raja Krishnamoorthi to run as the Democrat in Illinois’s 8th District? (As for the presidential primary, Politico’s Charles Mahtesian has five things to watch.)

Here are some other stories I read that you should know about before seeing the boss, riding the elevator or walking by the watercooler:

Eric Cantor takes sides while others avoid party fight (by Jake Sherman and Alex Isenstadt at Politico): His decision to endorse Kinzinger “represents the latest round of a generational battle within the House Republican Conference: A war between the younger conservative set of rabble-rousers, and the older, grayer Republicans.”

Obama is main target in House races, GOP says (by Josh Lederman at The Hill): Republicans also argued Monday that Democrats really need 37 seats — not the 25 they claim — to take back control of the lower chamber.

Barber will run for full term to succeed Giffords (by Billy House at National Journal): Ron Barber was Gabrielle Giffords’s district director and still running in an April 17 special primary election to fill out the remainder of Giffords’ term. Four Republicans also are running for the seat.

Who else for vice president but Marco Rubio? (by Stuart Rothenberg at Roll Call): “It isn’t easy to turn down your party’s nominee for president when he asks you to join the ticket. And even if the ticket loses in November, Rubio would be ‘next in line for the Republican nomination,’ always a valuable spot. He’d have a leg up on Jindal, McDonnell and the long list of Republicans — frankly, a more talented crop than this year’s — expected to contest for an open seat in 2016.”

Pelosi looms over contest for top slot on House Appropriations Committee (by Russell Berman at The Hill): This race is long off, but abortion politics could roil the race for the top Democratic spot on the panel, with Minority Leader Nancy Pelosi (D-Calif.) playing the role of a potential wild card.

Incumbents at risk in final N.Y. map (by Alex Isenstadt at Politico): Under a plan approved Monday by a three-judge panel based in Brooklyn, a handful of Democrats will find themselves with less safe seats, including Reps. Carolyn McCarthy, Nita Lowey, and Kathy Hochul, a freshman member whose Republican-leaning upstate New York-based seat is now even more GOP-friendly.

What did you read this morning? Share links in the comments section below or e-mail me a suggested story.

Follow Ed O’Keefe on Twitter: @edatpost

Further reading from the fine folks at PostPolitics:

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