Washington (CNN) Here are the stories our DC insiders are talking about in this week's "Inside Politics" forecast, where you get a glimpse of tomorrow's headlines today.

1) Selling trade tariffs to the Rust Belt

President Trump is slated to go to western Pennsylvania this weekend to campaign for the Republican candidate in the special election happening there next week. It's all happening in Pennsylvania's 18th district -- the GOP candidate is Rick Saccone and Trump plans to stump for him Saturday. As Wall Street Journal reporter Michael Bender tells us, there's another motivation for the road trip.

"This will put the president's political chips on the line once again, something he hasn't had much luck in the last six months," says Bender. "The more interesting thing, I think, is that this will give the President a chance to road-test his new trade policies, his new tariffs and while the President believes that this is the right policy, he's absolutely convinced on the politics of this. Remember, he rejected House Speaker Paul Ryan's border adjustment tax because it didn't have the snap. It didn't have the bumper sticker appeal ... that tariffs do. People understand intuitively what it means to slap tariffs on a foreign country and that sounds like winning to this President, so this will give the President a chance to see if this message has more resonance in the heartland than it does inside the Beltway, and frankly within his own West Wing."

2) About that PA 18th district race

That Pennsylvania special election will get a lot of attention in the final full week of campaigning, and suffice to say Republicans are nervous.

"The pucker factor is high," is how one top GOP strategist summed up the stress level.

In addition to the weekend presidential visit to help GOP candidate Rick Saccone, former Vice President Joe Biden is campaigning Tuesday for Democrat Conor Lamb. Biden's blue collar credentials make him welcome in a race where Lamb has asked most national Democrats to stay away.

GOP groups and their allies have poured heavy money into the race, but have not been able to move the numbers much. The worry now is that a small GOP lead in most polls might not be enough to overcome the Democrats' enthusiasm edge. More proof of the jitters: GOP operatives in Washington have been critical lately of the GOP candidate and his campaign, and even more critical of the Pennsylvania state GOP operation.

On paper, it is a safe Republican seat, and President Trump carried it by 20 points just 15 months ago. The fear among GOP leaders in Washington is that a Republican loss would be a giant statement about the midterm climate, and perhaps trigger another wave of incumbent retirements, which would only add to the GOP's problems.

3) Communications conundrum for the White House

With Hope Hicks' resignation comes a communications question for Trump's White House: who will take her spot? Even before Hicks announced she was leaving the administration, there had been chatter inside the West Wing about what the communications department needed. CNN's Abby Phillip explains where the holes are in the WH comms strategy.

"Some Trump allies from the outside have been advising them that what they need to do is get ready for the midterms, be able to have a mechanism to push out the good news ahead of 2018 -- especially on taxes which is something the president wants to tout more on the road. So the advice has been, 'Don't just replace the communications director, get some more strategic manpower, some people to think in a forward looking way,'" Phillips says. "The problem, though, is that even while they might want to do all of these things, it is hard to get people to want to work in the White House right now. They are trying to find professional communications people to come into one of the most chaotic places in the world right now and it is very, very difficult."

4) House Intel's Russia investigation "sputtering to a conclusion"

The House Intel's Russia probe is likely coming to a close soon. CNN's Manu Raju says the investigation is "sputtering to a conclusion" after turning into a political back-and-forth between the two sides.

"The Republicans on that committee really don't see really a reason to continue this investigation much longer. They believe they've come to a conclusion that there was no collusion between Trump associates and the Russians. The Democrats, on the other hand, say there have been a number of areas not yet investigated -- including Trump's financial records, including issuing subpoenas for records involving Jared Kushner, Donald Trump Jr.'s conversations with his father that he said were off-limits because they were protected by attorney-client privilege," Raju explains. "This investigation is coming to a very partisan and messy finish and there is certainly no consensus about what exactly happened in 2016."

5) WH approach to the opioid crisis

The White House seems to be on the same page about how to handle the crisis involving opioid addiction in the U.S.

Mary Katharine Ham of The Federalist explains the administration's approach to the issue that hits so many families so close to home.

"An interesting policy point came out of the opioid summit at the White House. That's an area of policy that the administration seems to have a more cohesive approach than other areas," Ham reports. "Governors [are] seeking these waivers that they're offering for Medicaid treatment of opioid abuse and substance abuse because there are some archaic rules in Medicaid funding that don't allow you to have, for instance, more than 16 beds at a center. That means there are long lines stacking up. Five governors have sought them and [the HHS Secretary] is asking for more to do that."