The Donald Trump campaign's ability to ignite controversy and dominate the news cycle can make it easy to forget there's more at stake on election day than the presidency.

The GOP is also at risk of losing control of the Senate, Sen. Majority Leader Mitch McConnell (R-Ky.) warned on Thursday, according to a report from the Associated Press.

Speaking to a Louisville civic group, McConnell described his party's chances of maintaining a Senate majority as "very dicey."

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This year, 24 Senate seats held by Republicans and 10 held by Democrats are on the ballot.

One of these seats belongs to Florida Sen. Marco Rubio (R), whose race is considered crucial to the GOP, Roll Call reports.

As it stands, the Republicans hold 54 seats in the Senate and the Democrats hold 46 (two of these are independents — Vermont Sen. Bernie Sanders and Maine Sen. Angus King — who caucus with Democrats). If Hillary Clinton wins the presidency in November — which current polls report is increasingly likely — Democrats would need to pick up four seats to take control of the Senate majority. If Trump wins, Democrats would need five, FiveThirtyEight explains.

From FiveThirtyEight:

"Of the 34 Senate seats up for grabs in 2016, here are the 10 that are closest to changing parties, according to the current polling averages: Arizona, Florida, Illinois, Missouri, Nevada, New Hampshire, North Carolina, Ohio, Pennsylvania and Wisconsin. All these seats, with the exception of Nevada’s, are currently held by Republicans, so Democrats need to win five of them to pick up a net gain of four and win six to pick up a net gain of five."

If Trump loses in these states, Republican Senate candidates would go down with him unless voters split their tickets — i.e. vote for Clinton or an Independent in the presidential election while voting for Republican Senate candidates. So there is considerable pressure on Senators like Rubio to sway voters who may not go for Trump without alienating Trump's base.

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A Friday Quinnipiac University Poll found both the Florida and Pennsylvania Senate races "too close to call." Rubio is running a tight race with both of his potential Democratic rivals Rep. Patrick Murphy and Rep. Alan Grayson. Florida's Senate primary will take place on August 30.

From Roll Call:

"Marco Rubio, an incumbent and onetime easy favorite, polled at 48 percent against Democratic challenger Rep. Patrick Murphy's 45 percent, the survey found. Rubio topped Democrat Rep. Alan Grayson — whose campaign has been hobbled by his ex-wife's allegations of domestic violence — 49 to 43 percent. The poll had a 3 percent margin of error in Florida."

Still, a Friday Marist poll reported by Politico had Rubio with a more substantial lead over Murphy — 49 to 43 percent.

Rubio's race has inarguably been colored by his tenuous relationship with his party's divisive presidential candidate, following a vicious primary season.

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Trump and Rubio have appeared to set their primary spats aside to some extent.

Rubio begrudgingly endorsed Trump in June and though they both appeared at Thursday speaking event in Orlando, they didn't appear together.

But Rubio has also distanced himself from Trump and rebuked the candidate's claim that President Obama founded ISIS on Thursday, the Naples Daily News reports.

“ISIS was founded by radical jihadists, not by the president,” Rubio said.

Though Rubio's odds go up-and-down a bit from day to day and poll to poll, his tepid support of Trump is consistently linked to his battle to keep his seat in the Senate.

When Rubio polls ahead, it is thought to reflect his efforts to keep Trump at arms length. When he polls poorly, it is typically linked to 'the Trump effect' — ie. Trump's lower poll numbers impacting down-ballot GOP candidates.

“Despite dozens of obvious and important reasons to drop his support for Donald Trump, Marco Rubio continues to stand by his endorsement of Trump to be the commander-in-chief, which is not just outrageous — it’s downright dangerous,” Sadie Weiner, a spokeswoman for the Democratic Senatorial Campaign Committee, told Politico.

Either way, it's clear that Rubio has a Trump problem that poses a significant threat to the Republican party.

"At this stage of the campaign, Republican U.S. Senate candidates may be running against their own presidential nominee, Donald Trump, as much as they are against their Democratic opponents," assistant director of the Quinnipiac University Poll Peter A. Brown remarked.