The biggest primary election spenders threw millions of dollars at opponents who went on to win. For some of those spenders, that meant their money went down the drain. For others, the returns have yet to come in.

The Federal Election Commission requires that outside spenders specify whether campaign dollars are being spent on general, primary, special elections or otherwise. With the last of 2014’s preliminary contests behind us as of this week, we calculated how much was spent against whom, and how those candidates fared in the primary.

Republicans saw intensive and expensive intra-party battles. The rankings below, with clickable features allowing readers to drill down on groups’ spending, reveal where the money went — and whether the target of those attacks suffered an early knock-out.

Because so much primary money was spent softening up presumptive November opponents, we opted not to calculate an explicit return on investment figure, as we’ve done in previous cycles following the general election. After all, the returns on that early spending won’t be clear for a few more months.

Here are a few of the takeaways:

• About $97 million in independent expenditures were made and categorized as “primary” spending. The numbers could change as reports continue to arrive or get amended.
• We identified the party affiliation of the outside group and the candidate targeted for about $95 million of this spending. Republican-leaning groups outspent Democrats about $59 million to $36 million.
• Republican groups spent far more boosting their own candidates than Democrats did: $35 million to $8 million.
• Democrats spent more attacking candidates of the other party. The vast majority of this is probably early general election spending classified as primary spending. Democratic-affiliated groups spent nearly $28 million attacking Republican candidates, whereas Republican groups spent just $2.5 million attacking Democrats. It’s important to note that these figures don’t include dark money “issue ads” that aren’t reported to the FEC; Republican groups like Americans For Prosperity have spent eight-figure sums bashing Democrats in unreported spending. Democrats have also spent under the radar, but generally in smaller amounts. You can find contracts for all political ad buys, including those by dark money groups on Political Ad Sleuth.
• Republicans spent far more bashing fellow GOPers ($21 million) in primary elections than liberal-leaning groups spent attacking Democrats (about $400,000). Note: These figures do not include special election spending.

Below is a breakdown of the top 10 primary spenders for the 2014 cycle.

The top 10 primary spenders for the 2014 cycle