Dr. Monica Wehby greets supporters at the headquarters in Oregon City, Oregon after winning the Oregon Republican Primary race for Senate on Tuesday, May. 20, 2014. (AP Photo/Steve Dykes)

11:55 a.m. Update: It's happened again: Wisconsin Democratic gubernatorial nominee Mary Burke has come under scrutiny following a Buzzfeed report that her jobs plan appears to have been copied from three other Democratic candidates from previous election years. Burke has reportedly cut ties with a consultant her campaign blamed for the copied material. 

The latest 2014 candidate to get busted for plagiarism is Monica Wehby, the Republican nominee for U.S. Senate in Oregon.

We say latest because it's happened over and over this election cycle. At a time when speeches, statements, policy platforms, college papers and just about anything else in writing can be easily crossed-checked online by opposition researchers and the media, it's no wonder offenders -- who often blame staff -- are being caught left and right.

Some plagiarism revelations are more politically-damaging than others. Below we look at the five biggest instances from this midterm campaign, ranked from most (#1) to least (#5) damaging. (Did we miss one? Let us know in the comments section.)

5. Tom Wolf: The Democrat running for governor of Pennsylvania fired a consultant after one of his opponents observed that his campaign took passages from energy company's reports and included them in his own policy plan. On the political spectrum, it ended up being a minor offense. Wolf won the primary and is heavily favored to defeat Gov. Tom Corbett (R) in November.

4. Greg Brannon: The obstetrician who ran for the Senate in North Carolina admitted last year to taking material from Sen. Rand Paul's Web site and putting on his own after the New York Times compared the two. Things got worse for him months later with more examples in a Buzzfeed report. Brannon never gained much traction in the Republican primary and never looked like a top contender -- even without taking the plagiarism allegations into account. Had he been a top recruit, the revelations probably would have been more damaging and he'd probably be higher up on this list.

3. Rand Paul: Okay, Paul's not up for reelection this year, but the Kentucky Republican is on this list because he has his sights set on a potential 2016 White House bid. Multiple outlets, beginning with MSNBC, reported in 2013 that Paul appeared to have plagiarized in speeches he delivered and a book he wrote. Paul did not argue he hadn't borrowed the material. He blamed the firestorm on "haters" and asserted that he simply wasn't diligent enough with citations. Paul's put it behind him. But if he runs in 2016, it could pop back up again.

2. Monica Wehby: The pediatric neurosurgeon was already an underdog against Sen. Jeff Merkley (D-Ore.) and this didn't help. On Tuesday, Buzzfeed reported that Wehby's health plan appeared to have been plagiarized from a survey conducted for a conservative group. A Wehby spokesman denied the claim. Then came another Buzzfeed story on Wednesday revealing that Wehby's economic plan appeared to be plagiarized, too. Wehby's campaign admitted the material was problematic and removed it from her campaign Web site. The campaign pointed fingers at a former staffer who has denied being the culprit. In short, things have gotten ugly. Wehby has already had to deal with another major distraction: A Politico report in May about how she was accused of stalking her ex-boyfriend. Overcoming two big-time distractions in any campaign is tough -- let alone for a Republican running in deep blue Oregon. 

1. John Walsh: There is no doubt that Sen. John Walsh's plagiarism at the U.S. Army War College was the was the most damaging of them all. The Montana Democrat was forced to end his campaign shortly after the New York Times revealed that he had lifted substantial portions of a major paper from other sources without any citation. The revelation was especially devastating because Walsh was emphasizing his military background and integrity as cornerstones of his campaign. It really hit him where it hurt the most.