Democrats now have their best shot at winning the House, according to Larry Sabato's Crystal Ball that just shifted 17 races in their favor.

Why it matters: It's the first time this cycle that the analysts at the University of Virginia Center for Politics are giving Democrats better than a 50% chance of winning the House. "[T]he Democrats now look like soft favorites to win a House majority with a little more than 100 days to go."

Expand chart Data: University of Virginia Center for Politics; Chart: Chris Canipe/Axios

Sabato, along with his Crystal Ball team at the University of Virginia Center for Politics, has been among the most conservative analysts, repeatedly telling us that House control was a coin flip, despite widespread projections of a Democratic takeover.

along with his Crystal Ball team at the University of Virginia Center for Politics, has been among the most conservative analysts, repeatedly telling us that House control was a coin flip, despite widespread projections of a Democratic takeover. "This president is not popular, and no one believes there is any chance the GOP comes out of this election with more seats than they hold now," the Crystal Ball's Kyle Kondik writes.

The big picture: Remember all the trends we've been telling you about...

Trump's presidential approval has hovered in the low 40s for months

for months Democrats have consistently led the House generic ballot

the House generic ballot Democratic candidates have outperformed in most special elections

in most special elections Republicans are defendin g 41 seats without an incumbent , compared to Democrats' 22 seats

g , compared to Democrats' 22 seats David Wasserman of the Cook Political Report recently moved 11 races toward Democrats, and tells us he sees a “blue wave” on Election Day, driven by suburban professionals.

Why it matters: The broad trend lines are bad for Republicans.

The number of districts in play is rising fast, and the vast majority are Republican seats. Numerous at-risk seats is the essential ingredient for a wave election.

in play is rising fast, and the vast majority are Republican seats. Numerous at-risk seats is the essential ingredient for a wave election. Democrats are raising more money overall than Republicans, which is exceptionally rare for a party out of power. Money can’t buy wins, but it sure as hell helps.

overall than Republicans, which is exceptionally rare for a party out of power. Money can’t buy wins, but it sure as hell helps. Democrats have turned out in record numbers in elections since Trump won. This is the most constant and reliable sign of sustained momentum.

Be smart: Republicans are counting on the strong economy, and could be helped by a lack of excitement among millennials and Hispanics. But presidential and party approval ratings are similar to those before past wave elections — bearish weather for the party in power.