WEDNESDAY’S CAMPAIGN ROUND-UP…. Today’s installment of campaign-related news items that wouldn’t generate a post of their own, but may be of interest to political observers.

* Sen. Blanche Lincoln (D-Ark.), facing an uphill re-election fight and a tough primary challenge, has a new television ad out this week that knocks labor unions. Seems like an odd strategy in advance of a Democratic primary.

* In the fight in Colorado between appointed Sen. Michael Bennet and former state House Speaker Andrew Romanoff for the Democratic Senate nomination, the first round goes to the challenger.

* In Connecticut, once thought to be a key Republican pick-up opportunity, a new Quinnipiac poll shows state Attorney General Richard Blumenthal (D) with leads of about 34 points over the top GOP candidates. In the Republican primary, wrestling executive Linda McMahon is now in the lead.

* On the national level, progressive groups are beginning to get more seriously involved in a primary fight against Rep. Bart Stupak (D) in Michigan.

* A new Field Poll in California shows Meg Whitman (R) way out in front over Steve Poizner (R) in the Republican gubernatorial primary, and enjoying a narrow edge over state Attorney General Jerry Brown (D).

* Speaking of California, if Rasmussen is to be believed, Sen. Barbara Boxer’s (D-Calif.) re-election bid is still struggling, and her lead over the Republican field ranges from two to six points.

* New York Republicans are still struggling to find a credible challenger to take on Sen. Kirsten Gillibrand (D) in November. Yesterday, former Rep. Joe DioGuardi (R) kicked off his campaign. DioGuardi, who served two terms in the House more than two decades ago, is best known as the father of one of the “American Idol” judges.

* Will former Wisconsin Gov. Tommy Thompson (R) take on Sen. Russ Feingold (D) this year? Thompson, who also served as Bush’s HHS Secretary and ran an unsuccessful presidential campaign, said the odds are “50-50.”

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.