Washington (CNN) With Labor Day rapidly approaching, one thing is becoming clear: All signs point to the Democratic wave growing rather than shrinking in the final weeks of the 2018 election.

: A new CNN poll shows Democrats with an 11-point edge on the generic ballot, a margin that, if history is any guide, promises major gains for the minority party. By comparison, Republicans held a 49%-43% edge on the generic ballot in the final CNN poll before the 2010 election, before the party picked up more than 60 seats that year. In the final CNN poll before the 2006 election -- where Democrats netted 30 seats -- the party had a 15-point generic ballot edge.

The generic ballot question -- "If the elections for Congress were being held today, which party's candidate would you vote for in your Congressional district" -- has functioned, largely effectively, as a sort of political weather vane. It tells us which way the wind is blowing and how strongly.

: Quinnipiac University has a new national poll out as well -- showing Democrats with a 9-point edge on the generic ballot. Self-identified independents -- traditionally the swing voting bloc in most elections -- favor a Democrat over a Republican by 12 points.

: The Cook Political Report, a nonpartisan election handicapping site, moved three more House races in Democrats' favor on Wednesday. According to Cook's House editor, David Wasserman , the moves now mean that there are "37 GOP-held seats as Toss Ups or more vulnerable (Lean/Likely Dem), nearly double the 20 we counted in January." In short: The playing field is getting bigger. And all the vulnerability is on the Republican side.

There's a tendency to avoid making any hard and fast predictions about where this election is headed because a) the old cliche that a month is like a year in politics and b) every "proven" quantitative measure showed Donald Trump losing in 2016 right before he won.

At the same time, there's very little evidence historically to suggest that the underlying dynamics of election cycles change much in their last 90 days or so -- barring some sort of catastrophic national or international event. Wrote Cook Political Report namesake Charlie Cook prophetically last week:

"In modern history, we've never seen a directional change in the last three months of a midterm election campaign. Waves can stay the same or increase in the closing months, but they don't reverse direction or dissipate."

That's very important to keep in mind amid the hand-wringing about people making inaccurate predictions because the election is soooooo far off. [Narrator voice: It's really not.]