On Monday, we looked at how the tea party isn't fairing so well thus far in 2014 primaries.

The main culprit: fundraising.

Tonight, the tea party's fortunes could take a momentary turn for the better (or get a lot worse, depending on the result). That's because its biggest cause célèbre, Ben Sasse, will learn his fate in a hard-fought and contentious Nebraska GOP Senate primary that gives the tea party arguably its biggest shot at a major victory.

But even if Sasse pulls off the win, it would say relatively little about the bigger picture for the tea party in 2014. That's because Sasse is in class by himself when it comes to tea party candidates this year, for two main reasons:

1. Sasse has outraised both of his top opponents: banker Sid Dinsdale and former state treasurer Shane Osborn.

2. Perhaps most importantly, he has been on the receiving end of a windfall of support from tea party and other conservative groups. A review of outside spending from the Sunlight Foundation shows about 90 percent of the $3 million spent by outside groups has benefited Sasse, either by building him up or tearing his opponents down.

No other tea party-aligned candidate has benefited from anywhere close to such a financial advantage, and only one other has even kept pace with his more establishment opponent: T.W. Shannon in Oklahoma.

In fact, a new study from the Brennan Center at New York University shows tea party Senate candidates in top races have been outraised 5-to-1 this cycle by more establishment-aligned candidates. Would-be tea party favorites, such as Reps. Paul Broun in Georgia, state Sen. Chris McDaniel in Mississippi, physician Greg Brannon in North Carolina, businessman Matt Bevin in Kentucky, retired Air Force Col. Rob Maness in Louisiana and 2010 nominee Joe Miller in Alaska, have all trailed far behind their opponents.

Here's how that looks in seven key races highlighted by the Brennan Center:

Data from the Brennan Center/Center for Public Integrity

McDaniel and Bevin, notably, face incumbents who are expected to far outraise their opponents. And the above chart features four races with incumbents.

But there are plenty of other races -- in Alaska, Georgia, South Carolina and Texas -- where candidates who have in the past identified with the tea party have struggled to raise basically any money or gain any measurable traction.

Sasse is the exception to that rule. He has essentially run a tea party campaign on an establishment candidate's budget -- and with tons of outside help. The GOP establishment, knowing this seat was safe from the beginning and probably liking Sasse just fine, never saw fit to rally around someone else.

One area where tea party candidates have outpaced establishment candidates is when these outside groups step in and -- as in the case of Sasse -- pick up the slack. The Brennan study shows tea party groups, on average, have spent about $350,000 more on their candidates than establishment groups have this cycle.

Courtesy: Brennan Center

But as the chart above shows, outside spending is a relatively small piece of the pie, as candidate fundraising (the blue) still reins supreme over outside spending (the red) in primaries. Tea party groups can pick a race or two and really flood the zone for their guy/gal, ala Sasse and Nebraska, but they haven't been well-funded enough to prop up poorly funded challengers across the country.

The tea party remains a sizable force in the Republican Party today, but unless its hand-picked candidates start raising money somewhere close to as well as establishment candidates, it's going to be much harder to pull many upsets -- or for the Ted Cruz caucus of the Senate to grow.

The tea party, essentially, needs more Ben Sasses.