Some of the most competitive races in Washington State this year could determine which Party controls the Washington State Legislature. The margins are razor thin in both the State Senate, controlled by Republicans 26 to 23, and in the State House controlled by Democrats 50 to 48.

Over the next few days, KING 5 will focus on key legislative races, starting with the Senate.

Key races to watch:

District 17, Vancouver, Clark County.

This is an open seat, currently held by Don Benton who chairs Donald Trump’s local campaign.

Republican Representative Lynda Wilson held a narrow lead in the August Primary over Democrat Tim Probst.

Money Raised: Wilson $429,858.42, Probst $380,895.28

Independent Spending: $233,212.39 in support of Wilson, $378,036.08 in opposition.
$169,380.85 in support of Probst, $651,445.50 in opposition.

District 5 , East King County, Carnation, North Bend, Snoqualmie, Issaquah, parts of Renton.
Republicans are targeting this currently Democratic held seat.
Incumbent Mark Mullet (D) held a narrow lead over State Rep. Chad Magendanz in the primary.

Money Raised: Mullet: $494,211.17, Magendanz $456,013.37

Independent Spending: $226,105.05 in support of Mullet; $520,103.94 in opposition.
Magendanz: $302,106.25 in opposition.

District 28, Pierce County, University Place, Lakewood, Steilacoom, Dupont, part of Tacoma

Incumbent Republican Steve O’Ban led Marisa Peloquin (D) in the primary.

Money Raised: O’Ban $490,876.45, Peloquin $335,936.31.

Independent spending: $368.78 in support of O’Ban, $414,113.94 in opposition.
$109,122.93 in support of Peloquin, $171,322.97 in opposition.

District 41, part of King County including Bellevue, Mercer Island, Newcastle, Issaquah, Sammamish

Republican incumbent Steve Litzow narrowly trailed first-time candidate Lisa Wellman (D) by under 500 votes. This week, President Obama endorsed Wellman in the race, as part of a nationwide strategy to flip state legislative seats.

Money raised: Litzow: $752,370.51, Wellman $413,402.55
Independent spending: $267,146.32 in support of Litzow, $360,024.58 in opposition.
$58,780.09 in support of Wellman, $398,488.63 in opposition.

Democrats are aggressively targeting both legislative districts 28 and 41, hoping they benefit from a “Trump effect” down ballot.

“Trump is toxic for a lot of folks in this state, that’s why you see a Republican try to disassociate from his own Party,” said Sen. Sharon Nelson, the Democratic Minority Leader. “We believe it will have an influence down ballot.”

Senate Republican leaders, meanwhile, downplay the potential impact of a controversial GOP nominee. They’ve focused instead on a campaign message against taxes.

“If the Democrats take control I believe the solution will be a state income tax,” said Sen. Ann Rivers, on the Senate Republican Campaign Committee.

“I think that any time you have divided houses, it’s actually healthier.”

Senate Democratic leaders refute the claim that their candidates want an income tax.

"Our swing district candidates have all been crystal clear that they won't support an income tax, and it's appalling that Republicans are basing their entire campaign strategy around flat-out lies,” said Alex Bond, political director of the Senate Democratic Campaign.

The above fundraising figures are from the latest Public Disclosure Commission totals.