Campaigns and outside groups have already poured tens of millions of dollars into this year's battle for control of the Minnesota Legislature, with DFL-aligned groups holding a significant cash advantage headed into the final push before Election Day.

With all 201 state legislative seats on the ballot this year, the outcome of these contests will determine whether state government remains divided as it is now, with Republicans holding a majority in the Senate and the DFL in the House, or if one party controls both chambers.

Those stakes have prompted heavy spending from candidates and groups on both sides of the political divide.

The levels appear on track to exceed the $30 million spent in 2016, the last time all seats were up for a vote.

The results could have significant implications for state policy in 2021 and beyond: The next Legislature, along with DFL Gov. Tim Walz, will face a looming budget deficit, a pandemic and the decennial redrawing of state and federal political districts.

Outside groups reported spending about $16 million as of Oct. 19, the end of the preelection filing period.

While the spending includes a number of contested races in the August primary, reports show much of the focus is on the state Senate, where Democrats are vying to gain at least two seats needed to overcome the GOP's 35-32 majority and flip the chamber.

The reports, due to the state Campaign Finance and Public Disclosure Board on Monday, provide a snapshot of which districts have emerged as the biggest battlegrounds heading into the final stretch of the campaign. More than $1.5 million in independent expenditures have been reported in the northwest metro rematch between Sen. Warren Limmer, R-Maple Grove, and Democrat Bonnie Westlin. Outside groups spent more against Limmer than any other legislative candidate as of Oct. 19.

GOP-held seats covering the Burnsville, Stillwater and Rochester areas have also attracted more than $1 million in spending from outside groups.

The filings suggests freshman Sen. Matt Little, DFL-Lakeville, remains a top target for Republicans. GOP groups reported spending more than $300,000 to defeat Little, who faces a challenge from Lake­ville school board Chairman Zach Duckworth. DFL groups, meanwhile, have spent more than $400,000 to back Little.

Westlin and Democrat Aric Putnam, who is running against GOP Sen. Jerry Relph for a St. Cloud seat, have seen similar sums spent against them.

Both candidate and independent expenditure reports cover contributions and spending since January, including some ahead of the August primary.

The final tally for mailers, digital ads and TV spots will rise as the election nears. For example, Everytown for Gun Safety has pledged $1 million on a late push to flip the Senate, the Minnesota Reformer reported. Current reports show the group spending more than $400,000.

That additional spending could further tip the scales for the DFL in a year when polling shows Minnesota voters breaking for Democrats in the presidential election.

Groups backing DFL challengers and incumbents, including Alliance for a Better Minnesota (ABM), had outspent their GOP counterparts as of the filing deadline.

ABM, funded by top DFL donors and labor unions, led all other outside groups with $2.9 million spent as of the October deadline.

But GOP-aligned independent expenditure committees are also spending hundreds of thousands of dollars. Advance Minnesota, backed by business and pharmaceutical groups among others, has spent more than $1.1 million so far.

The election has also sparked a fundraising boom for candidates running for competitive seats. At least 14 legislative candidates reported raising more than $100,000 this year, with two crossing the $200,000 threshold. Lindsey Port, challenging GOP Sen. Dan Hall of Burnsville, reported raising more than $237,000. Hall, the incumbent, raised $58,000.

Democrat Ann Johnson Stewart also led the pack with a $232,000 haul for an open Senate seat in the western suburbs. Her opponent, Republican Greg Pulles, has taken in more than $130,000 so far.

The state DFL Party, meanwhile, reported raising more than $9 million for state races, 10 times the $831,000 raised by the Minnesota Republican Party's state effort.

House and Senate caucuses — which like state political parties can spend independently on behalf of candidates — are also reporting record fundraising.

Four years ago, the Senate GOP caucus won a majority despite being outspent 4-1, said Senate Majority Leader Paul Gazelka, R-East Gull Lake. The $1.9 million the caucus raised this year is more than four times the previous record.

"I said we're just never going to let that happen again," he said of being outspent by a wide margin in 2016. "And so money will not be the determining factor in this election. We're able to compete."

Even so, the Senate DFL's fundraising dwarfs his haul: The caucus raised $5.6 million this year for its bid to retake the upper chamber.

Democrats in the House are defending a 16-seat majority they won in 2018. Speaker Melissa Hortman, DFL-Brooklyn Park, said her caucus also has seen a bump in activity. It reported raising more than $4.5 million this year.

House Republicans, meanwhile, raised $1.36 million for their fight to win back the majority in that chamber. Hortman said the numbers indicate high enthusiasm among Democrats.

"[To] be exceeding our 2018 markers, in the midst of a pandemic, can only mean the Democrats are very motivated to be involved in this election and to make sure that we win," she said.

Star Tribune editor Chase Davis contributed to this report.