CORRECTION (7:19 p.m.): A previous version of this post inaccurately stated that the National Republican Senatorial Committee was advertising in the Connecticut Senate race. They are not.
The Democratic Senatorial Campaign Committee has placed a $526,000 ad buy in Arizona for the week of Oct. 2 to Oct. 8, their first independent expenditure in the state's open-seat Senate race, according to a Democrat who tracks ad buys.
It's the first DSCC IE ad buy in the state, which has recently started looking like a potential Democratic pickup opportunity. The fundamentals of the red-tilting state favor Republicans, and GOP Rep. Jeff Flake has long been considered the favorite in the race. But former U.S. Surgeon General Richard Carmona is a strong Democratic recruit, and recent polls show that the race has tightened significantly. The presidential contest has also gotten closer.
Last week, Democratic outside groups VoteVets.org and Majority PAC made their first foray into the race with a $280,000 ad buy hitting Flake on veterans issues.
The DSCC is also on the air in two other states that had once been regarded as likely Republican wins: North Dakota and Indiana. Meanwhile, the NRSC is spending in Maine, an open seat that was previously seen as beyond their reach.