– U.S. Rep. Erik Paulsen, who spent more on his own re-election last year than any other Minnesotan in Congress, is continuing to spend big this year as he prepares for what is likely to be another competitive race in 2018.

According to recent Federal Election Commission filings, Paulsen laid out $198,087 from his campaign account during the first three months of this year — more than any other federal representative from Minnesota except for Rep. Keith Ellison, whose $879,852 in spending so far in 2017 was mostly tied to his unsuccessful bid to lead the Democratic National Committee.

Now Minnesota’s senior elected Republican in Washington, Paulsen in the previous election cycle spent far more defending his congressional seat last year than any other Minnesotan in Congress: $5.8 million. Most of that was on media advertising — more than any of the 435 other members of the U.S. House, according to data compiled by the Center for Responsive Politics in Washington, D.C.

As a five-term incumbent in a seat long held by Republicans, Paulsen was left to purchase many of his own campaign ads in his race against DFL challenger Terri Bonoff, as GOP-aligned national groups focused more on the unsuccessful bid to unseat U.S. Rep. Rick Nolan in northeastern Minnesota.

Paulsen’s campaign spending, which has accelerated in recent years, is on a similar pace this year as the Eden Prairie congressman heads for what could be a similar dynamic in 2018. Democrats are already eyeing his western Hennepin County district, which recent Democratic presidential candidates have carried, as the Trump presidency forces Paulsen to take a series of tough votes in Congress.

“Our fundraising and spending is just a reflection of the competitiveness of our district and taking [that] seriously,” said campaign spokesman John-Paul Yates. He added that Paulsen “has chosen to rely on himself. … It’s simply a reflection of him wanting to make sure that he’s in a strong position politically.” Paulsen expects a tough challenge in 2018, according to Yates.

No DFL candidates have entered the race to challenge Paulsen, a member of the influential Ways and Means Committee. A potential challenger talked up by some DFLers is Dean Phillips, a Minnesota businessman whose family started the Phillips Distilling Co. The Democratic Congressional Campaign Committee is gearing up to target Paulsen, already running digital ads attacking his committee vote in favor of repealing the Affordable Care Act, and again this week over the GOP’s latest health care proposal.

Paulsen has been diligent about spending money to ward off political challengers. In 2015 and 2016, he more than doubled his campaign spending from the previous two election cycles. He began increasing spending beyond commercials, mailers and polling, pouring campaign dollars back into courting wealthy Republican donors in Washington and around the nation. Paulsen spent almost $140,000 on expenses marked as travel and airfare, visiting Naples, Fla., and Las Vegas.

Campaign filings that detail spending before the election so far this year show expenses at high-end hotels and resorts in South Carolina, Utah and California. The expenses are legal and appear “fairly consistent” with fundraising expenditures permitted for House members, according to Citizens for Responsibility and Ethics in Washington.

Paulsen ended last year with $373,169 in his campaign account, and in the first three months of 2017 he raised $489,911. One of Paulsen’s largest expenditures so far this year was $69,926 for finance consulting. He also spent $14,287 on polling in March as the GOP’s proposal to repeal the Affordable Care Act was being debated.

While Paulsen’s own fundraising fueled his 2016 bid, other Minnesota congressional races saw an influx of money from outside groups. Nolan spent $2.9 million from his own campaign account to fend off a $3.7 million challenge from Republican Stewart Mills. The race became one of the most expensive congressional contests in the country last year as Republican and Democratic national groups together spent more than $17 million on ads.

Next year promises to be the most eventful and expensive on the congressional front in several decades. Democrats are likely to target the districts held by Paulsen and by freshman U.S. Rep. Jason Lewis in the southeastern Twin Cities metro. Republicans will make a play for the southern Minnesota seat held by DFL U.S. Rep. Tim Walz, who’s running for governor, and two other House districts held by DFLers but which Trump won last year: Nolan’s seat and the western Minnesota seat long held by U.S. Rep. Collin Peterson.

Lewis won in 2016 with just $1 million of his own campaign spending, compared with $4.7 million from Democratic opponent Angie Craig.

Lewis raised $309,000 in the first quarter of this year. As a political newcomer in a swing district, he’s largely saving campaign spending until the election heats up next year; Craig is leaning toward running again.

In the 2016 race for Paulsen’s seat, Bonoff, a former state senator, spent nearly $2 million from her own campaign account to take on the Republican. Outside groups poured another $5.7 million into the district, the majority of it from Democratic-aligned interests. Paulsen ultimately won by about 14 percentage points.

Yates said the campaign has always been mindful of drawing an opponent of Bonoff’s caliber. “We wanted to be prepared for when it happened,” he said, “instead of relying on what the party would do to support [us], which is really out of our control.”