In mid May, senior House Republican officials huddled at the Hyatt on the Chesapeake Bay to discuss their messaging plan to save the House majority.

One of their guest speakers was the well-respected election forecaster Charlie Cook, who founded the non-partisan "Cook Political Report." According to sources in the room, Cook gave the Republican staffers a bleak view of the midterms. He said he was deeply skeptical that simply touting the economic wonders of tax reform would be enough to save the House.

Cook confirmed this to me via email: "I told the group that the tax cut did help among Republican voters, but helped only a little and temporarily among independents and did nothing with Democratic voters.”

"The essence of what I said was that if they were going to rely primarily on the tax cuts to hang onto their majority, they were unlikely to succeed.”

"Even with the uptick in President Trump’s numbers and in the generic ballot test, I still think it is pretty uphill for them to hang onto their House majority. I use the metaphor of a Democratic tidal wave up against a Republican sea wall. In the House, the wave looks taller and stronger than the wall, in the Senate, the wall looks taller than the wave."

Sources in the room walked away with different impressions of Cook's presentation. A non-leadership source told me it should be a wake up call to leadership, who are fixated on using tax reform as a selling point to voters. But leadership sources disputed that to me, saying tax reform is just one message in their toolkit, though an important one.

Some were unimpressed by Cook's presentation and felt that other pollsters who presented to the group — including Kristen Soltis Anderson and David Winston — gave compelling reasons to think messages of tax reform and economic growth would help them this year.

One House source pointed out that just a week after Cook's presentation, his colleague Amy Walter wrote: "Part of the reason for the increase in enthusiasm is the fact that Republicans now have something around which to rally — specifically an improved economy and tax cut law."

The bottom line: Republicans have a heck of a hard job saving the House this year, as the president's party almost always loses seats in his first midterm. Trump's approval rating remains under water. Democrats are more energized than ever, and there are serious questions about whether Republicans will be motivated enough to show up and vote in the numbers required to save the House.