This is a fascinating and potentially very important story that hasn't gotten a ton of press. Theoretically, it is possible that this gives the GOP 53 seats. However that is probably unlikely.
First, Menendez has to be found guilty. This in itself is somewhat of a longshot because of some recent court decisions that have weakened the prosecutorial power for corruption charges like this. This will be pretty difficult to prove beyond a reasonable doubt as a result. But it's not out of the realm of possibility. Then he also has to step down (lol yeah right) or be voted out. Getting voted out is also unlikely because it requires 67 votes and there's no way dems would be on board with this unless Christie gave some kind of promise that he'd replace him with a Democrat to match the voting tendencies of the state. They're not going to vote to give the GOP another senate seat.
So while it's an interesting story, and while it does have potential to have national consequences, it's still very unlikely that much of anything comes of this.
Keep in mind the indictment happened before this Supreme court ruling -
"The Supreme Court unanimously overturns a public corruption conviction of former Virginia governor Robert F. McDonnell. McDonnell and his wife, Maureen, were convicted in 2014 for accepting luxury gifts and cash from a businessman in exchange for McDonnell using the office of governor to help the businessman.
The justices took issue with what constitutes an “official act,” arguing in McDonnell's case, it was overly broad.
Menendez's lawyers perk up at this. The senator is accused of trying to influence executive decisions, not of writing laws that helped his buddy, they plan to argue, and they will ask the judge to throw the charges out altogether.
“There is a very real chance this case might be dismissed,” as soon as it gets started, Harrison said."
The ruling could have very big ramifications on this case.