Fed chair Powell is going to have to hold the line in order to keep the calm in today's policy decision. Amid constant pressure from US president Trump, we're already starting to see some policymakers flip in recent weeks namely Bowman and Waller. They're both now the most dovish members on the board and voting members mind you.Does that mean we're seeing three separate groups now at the Fed?One wanting to cut rates as soon as this month (Bowman and Waller), another anticipating roughly two rate cuts, and the other being one expecting to keep interest rates unchanged through the year amid potential inflation risks.Amid tariffs and trade uncertainty still persisting, the "right thing" would be to play it safe and keep rates unchanged today. And that is what is going to happen. But what about September?The statement language is not likely to allude to anything or pre-commit to anything surely. The Fed will want to wait on more data before deciding so I would not expect a dovish tilt to tee up a rate cut as their next move just yet. It would be silly to remove that flexibility unless the dovish dissents are starting to grow even bigger, which for now seems limited to just Bowman and Waller.So, any major communication about shifts in their forward guidance will come from Fed chair Powell's press conference.He will have to walk a fine line in retaining the current wait-and-see mode, reaffirming that the Fed is still in no hurry to be cutting rates just yet. The question is, how much acknowledgement will he give to the more dovish dissents or will he even push back on that in slapping back Trump and his mockery?One can expect his Q&A later to be flooded with questions about a divide in the Fed outlook and also on the central bank's independence. Other than that, it will be a question of is Powell going to confirm that the Fed will have enough "clarity" by September to possibly decide on a rate cut.Trump is already settling key trade deals in the meantime, albeit some being more makeshift, and that will at least preserve a less erratic outlook for the next few months.However, it is perhaps an issue back home that the Fed has to be worried about and that is the passthrough of tariffs to domestic inflation. We've seen subtle evidence of that in the June CPI report already, especially when you drill down to core goods inflation. Just to give an example, MNI's calculation of themedian of 56 core goods items accelerated to 0.44% m/m last month as compared to 0.29% m/m in May. And that's the highest figure since August 2022.There's still a balance to be struck in getting a full picture of whether this is all tariffs-related though. At the end of the day, it's all about how the tariffs passthrough is going to be split between consumers, businesses and importers. That may take some time to settle.As things stand, traders are pricing in ~66% odds of a September rate cut. And that's the risk probability to watch going into the Fed meeting today. It's all about how that will shift depending on Fed chair Powell's message to markets. This article was written by Justin Low at investinglive.com.