Down this road lies real danger for Republicans. Here's why.
At the core of this strategy is the idea that the average voter will differentiate between Trump and congressional Republicans. Or, even more unlikely, that people will separate Trump's words from their actions.
If the last two midterm elections — 2010 and 2014 — have taught us anything, it's that the president's party goes as the president goes. In 2010, Democrats lost 63 House seats; four years later they lost 23. In each of those elections, Democratic House members did everything they could to run from Obama and some of his less popular policies — like the Affordable Care Act.
Now consider that Trump is, at least according to early polling, one of the most divisive and unpopular presidents in modern history. And that the Democratic base has been activated by the early days of the Trump presidency.
Given that, it's very hard to imagine that (a) the election will be anything but a referendum on Trump's first two years in office and (b) voters will separate their feelings about Trump from their feelings about congressional Republicans.
Imagine it's the fall of 2018. An endangered Republican — say, California's Darrell Issa — goes on TV with ads touting the accomplishments of the Republican Congress, making no mention of Trump. His Democratic opponent responds with ads highlighting all of the various controversial things Trump has said in the first two years of his presidency.
The idea that voters would distinguish between Issa's accomplishments as part of a Republican-led Congress and their view of Trump is nonsensical. The average voter will make no such distinction. If Trump is popular — or not that unpopular — then the likes of Issa can win. If Trump is unpopular, Issa likely loses.
This is a strategy built of necessity for congressional Republicans. Confronted with the prospect of President Trump, they had only two options: Turn against him each time he says something outlandish/untrue or try to ignore most of what he says and stay focused on the policies he can help get enacted.
They chose the latter. Which keeps them from being blasted day in and day out by the head of their party, who is also sitting at 1600 Pennsylvania Avenue. What it doesn't do — no matter what they think today — is allow them to effectively distance themselves or run away from Trump at the ballot box in November 2018.
The 2018 election will be a referendum on Trump. Period. Congressional Republicans just have to hope what he accomplishes outweighs what he says in voters' minds. It's a very risky gamble.