The first general election contest since President Trump took office kicks off in Kansas, with what was once expected to be an easy win for Republicans turning unexpectedly fierce.

Republican Ron Estes, a two-term state treasurer, is still the favorite to win the Wichita-area 4th congressional district that Trump carried by nearly 30 points, but Republicans in the state predict that it'll be a closer-than-expected margin with Democratic candidate James Thompson.

The Hill will be updating this blog as polls close at 8 p.m. EST and votes start to roll in.

AP calls race for Estes

Updated 10:49 p.m.

The Associated Press has called the race for Estes in what was a closer-than-expected election

AP called it with Estes leading by 6 points, with 88 percent of precincts reporting.

While Thompson wasn't able to deliver a major upset for Democrats, the closeness of the race will be a blow to Republicans and likely energize Democrats for future elections.

Estes widens lead with most precincts reporting

Updated 10:45 p.m.

With 88 percent of precincts reporting, Estes has strengthened his lead by nearly 6,000 votes.

But the Associated Press has yet to call the race.

Estes pulls ahead

Updated 10:10 p.m.

With 63 percent of precincts reporting, Estes has pulled ahead with a 2,371-vote lead.

Estes, Thompson separated by less than 1,000 votes

Updated 9:43 p.m.

The race has significantly tightened with Estes only trailing by 703 votes.

The Kansas Republican has won seven counties so far, while Thompson still maintains a lead in Sedgwick County.

Important detail that suggests Estes is the favorite to pull this out by a small margin. #KS04 https://t.co/Q6MyhHu4N1 — Dave Wasserman (@Redistrict) April 12, 2017

Big focus on Sedgwick County

Updated 9:27 p.m.

Again -- we should expect about 2/3rds of all votes to come from Sedgwick https://t.co/eUTnhQfP3Z — Kyle Kondik (@kkondik) April 12, 2017

Thompson’s lead tightens as rural counties roll in

Updated 9:23 p.m.

As rural county numbers roll in, Estes is starting to cut more into Thompson’s lead. He has now won Comanche, Kiowa and Pawnee counties.

Estes is now only trailing by a little more than 3,300 votes. All eyes will likely be on Sedgwick County.

Estes leading in four counties but still behind

Updated 9:00 p.m.

Results in Barber, Edwards and Butler counties show Estes with an early lead, but numbers haven’t changed much.

Estes won Pawnee County, which only cast 62 votes. He won 44 of those.

With 2 percent of precincts reporting, Thompson has 14,722 votes, while Estes’s vote total has climbed to 9,425.

Early vote numbers look good for Democrat Thompson

FiveThirtyEight analyst Harry Enten considers that the early vote numbers explain the GOP's last-minute push in Kansas.

I'm beginning to see why Republicans were freaking out about KS-4. Still time to turn it around in E-Day vote, but boy. — (((Harry Enten))) (@ForecasterEnten) April 12, 2017

Thompson with very early lead as results trickle in