Here's more evidence the Republican Party is breaking up with Donald Trump -- when it's politically convenient.

House Republicans' campaign arm is running a TV ad praising one of their most vulnerable incumbents, Rep. Bob Dold (R-Ill.), for standing up to -- not with -- Trump.  House GOP candidates have run their own ads ditching Trump, but this is the first time that the official campaign arm has put an ad in this vein on the air.

In the ad, the narrator says: "Dold is an independent voice who stood up to Donald Trump months ago." The ad clips to Dold on CNN saying: "I think Donald Trump has disqualified himself." (The visual effects make very clear that Dold ditched Trump in March, waaaay before the world knew about Trump's "Access Hollywood" tape.)

This is a notable moment in the 2016 election: House Republicans are spending money to tell voters one of their candidates dislikes their own presidential nominee. It may not be the last time they do this, but it's also not likely to become a widespread trend.

Many House Republicans are hanging on in spite of Trump's dip in the polls. Post-ABC News polling after The Tape shows likely voters favor a generic Democratic member of Congress over a generic Republican by just a few points -- hardly a wave. In fact, in some competitive districts, Trump is actually leading, like Nebraska's 2nd, where Trump is up four points over Clinton and so is the Republican trying to unseat Rep. Brad Ashford (D). In the Senate, Republicans are largely defying Trump's gravitational pull.

The reverse is true for Dold's seat in the northern Chicago suburbs. It is one of the most Democratic districts Republicans hold this cycle. Polls show Clinton leading Trump here by some 20, even 30, points. If Republicans want to keep Dold in the House, they figure they have no choice but to shout from the rooftop how much their candidate dislikes Trump.

That's one reason why it's unlikely we'll see a full-scale party break-up with Trump, as some had predicted. He's not such a drag on everyone -- yet. Even though House Republicans are defending eight of The Fix's most recent top 10 races, they have such a large majority (58 seats) that losing it doesn't seem to be in question unless Trump loses to Clinton by some 10 points.

But still, the fact that this "Bob Dold is standing up to Donald Trump" ad exists is a testament to how head-spinning the 2016 election is. In fact, a lot about right now feels like the twilight zone.

This week, the Democrat in an Orange County, Florida, property appraisal race (yes, property appraisal) was the subject of a mailer by Republicans trying to link him to Trump. "Rick Singh = Donald Trump," it reads.

In late October, CNN reported that Florida Democratic Senate candidate Rep. Patrick Murphy's (D) father was pictured with Trump at a groundbreaking event, despite Murphy denying that his family had business ties with Trump. A GOP operative seized on it, which had the effect of a Republican attacking a Democrat for being associated with a Republican presidential nominee.

House Speaker Paul D. Ryan (R-Wis.) has officially broken up with Trump, leaving every Republican to decide for him or herself what to do.

And then there's Rep. Jason Chaffetz (R-Utah), the ambitious and powerful chair of the House Oversight Committee. Twenty days ago, he was so over Trump. On Wednesday, he essentially flip-flopped and jumped back on board, marking at least the fifth or so Republican to endorse, then unendorse, then re-endorse Trump.

So, to sum up: This is a weird election. If you're a Republican, it isn't that there's no one, great answer about how to deal with Trump -- there aren't very many good answers, either. In Dold's case, Republicans decided the best way for him to survive is to run as far and fast as he can.