THE AD WRITES ITSELF…. For several years, Democratic opposition to blank-check spending bills for the wars in Iraq and Afghanistan were the single most popular area of attack for Republicans. To vote against “funding the troops,” the GOP said, was to betray the nation and those who wear the uniform. It was the basis for countless speeches, ad campaigns, and attacks.

Whether a lawmaker was fully satisfied with individual provisions in the spending bill was irrelevant — the troops are fighting wars and they need the money. Excuses won’t protect them or give them the resources they need.

In fact, just a year ago, House Minority Leader John Boehner (R-Ohio) argued, “[T]here is a clear distinction between saying you support the troops and backing up those claims with genuine action. [Obama] once said ‘we shouldn’t play chicken with our troops’ when it comes to funding our troops in harm’s way, and [Hillary Clinton] urged General Petraeus at the start of the surge to request ‘every possible piece of equipment and resource necessary’ to keep our troops safe. These words turned into little more than empty rhetoric when both proceeded to vote against funding our troops last year.”

Last week, of course, the situation was reversed, and it was House Republicans “voting against funding our troops.” This week, the DCCC is unveiling a series of 60-second radio ads targeting seven vulnerable GOP incumbents on their votes. This one, for example, goes after Rep. Lee Terry (R) of Nebraska.

“Around here, we recognize Independence Day with parades … and picnics … maybe a few fireworks.

“But July Fourth is about more than that. It’s about remembering those who fought for our freedoms. And those still fighting today.

“Congressman Lee Terry used to understand that. When George Bush asked, Congressman Terry voted to fully fund our troops in Iraq and Afghanistan. And, last year he said, quote, ‘We must give our military every resource it needs.’

“Seems like Congressman Terry is playing politics now. Last month Congressman Terry voted AGAINST funding for those same troops. It’s true: vote number 348 — you can look it up.”

Republicans did make this easy for Dems. Indeed, all the DCCC had to do was pull up the same kind of radio ads Republicans used before and insert GOP names.

As a substantive, policy matter, lawmakers can have completely legitimate reasons for voting against military spending measures, and opposition to these expenditures does not make one an unpatriotic terrorist sympathizer.

But Republicans opened this door. It’s hard to blame Democrats for walking through it.

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.