Update: After the deadliest mass shooting in American history early Sunday morning in Orlando, Volsky's tweetstorm is drawing attention again. With the debate over guns already picking up, we are re-upping this piece from December about how the NRA's influence isn't really about campaign contributions.

Following the massacre in San Bernardino, Calif., on Wednesday, ThinkProgress's Igor Volsky captured the hearts of gun control advocates with a series of tweets comparing reactions to the shooting by Republican members of Congress with the amount of money they'd received from the National Rifle Association.

For example:

And so on.

The core construct Volsky used — prayer means nothing compared to policy changes — met with harsh criticism from those who thought it disparaged the value of prayer, particularly in emotional moments. But there's another problem with Volsky's tweets: They reinforce the naive idea that campaign spending creates members of Congress beholden to outside interests.

That's an admittedly controversial point. There's a subset of American politics that is heavily invested in the idea that the road to bad legislation is paved with checks from wealthy donors. But that's not generally the case — as Volsky’s tweets inadvertently make clear.

Let's take six members of the House who tweeted their condolences and prayers, prompting Volsky's critique. Two of them are in the series of tweets above; the other four can easily be seen in Volsky's stream. Here's how much of the total money raised by those six candidates came in the form of contributions from the NRA. The dark red slivers are the money from the NRA.

The highest percentage was given to Rep. Bob Goodlatte (R-Va.), who got 0.5 percent of his campaign money from the organization — a half-penny of every dollar. The idea perpetuated by Volsky (and often by other critics of campaign finance) is that this tiny fraction of the candidate's overall support is enough to get him to vote strictly in favor of the NRA, no matter what happens. Of course, the NRA wasn't one of the top 20 donors to Goodlatte in terms of PAC and individual giving — but we are meant to assume that their relatively modest check has the effect of a manacle around the wrist of his vote-casting hand.

Volsky's point about the independent spending for Senate candidates shows a bit more relevance to the campaigns.

But there are far fewer independent expenditure campaigns on behalf of candidates, meaning that any contribution will often make up a larger percentage of the total. Combining spending by the NRA and its legislative action arm, the NRA provided about 13 percent of the outside money that backed Sen. Thom Tillis's (R-N.C.) winning bid. But the NRA itself was still only the 10th largest contributor to independent expenditures in that race. More money was spent for Tillis by the National Republican Senatorial committees, the Chamber of Commerce and Crossroads GPS than the two NRA organizations combined.

If you include the money raised by the campaign itself, the amount provided by the NRA's outside expenditures shrinks even further.

This doesn't disprove the idea that the NRA's contributions influence Republican voting any more than Volsky's tweets prove that they do. But considering how little of those House campaigns' fundraising came via the NRA, it's more likely than not that the relationship isn't quite that easy.

So why would Bob Goodlatte take the side of the NRA? Well, for one thing, he's a Republican. There are few organizations more popular with the Republican base than the NRA; it is as popular on the right as Planned Parenthood is on the left. The value of an NRA endorsement is like the value of an endorsement from the police officer's union: Even if they don't spend a dime, it does a lot of good with certain constituencies.

More broadly, the value of making a donation to a campaign isn't that it buys you a vote; it's that it buys you an audience. A study released in 2014 showed that it was easier for donors known to an elected official to get a meeting, and when the meeting was scheduled, the staff representative who attended was more senior than those who met with non-donors. Organizations aren't making contributions so that they ensure a certain outcome on the floor, they're ensuring that if the senator is looking for a fourth for his golf match, they might get a call. Then, businesses and interest groups make their case to the elected official — or even offer help in drafting policy. This isn't great, of course, but it's not as simple as we often pretend. It's easy to see how this gets shortened into money-buys-votes, but that's not actually the transaction.

Especially when the donor is contributing a tiny fraction of everything the candidate received. The power of the NRA lies in the cause they advocate. Gun rights has a strong base of support, and one that votes heavily Republican. The NRA didn't need to give Goodlatte a dime, and his reaction to San Bernardino would likely have been the same.