Although Texas is a predominately red state, it appears incumbent U.S. Sen. Ted Cruz may have his hands full come November when he squares off against Democratic challenger Beto O’Rourke.

The congressman from El Paso has out-fundraised Cruz by more than $10 million since joining the race, according to reports.

But according to the Cruz campaign, O'Rourke may have erred this week in calling for the impeachment of President Donald Trump following the president's Helsinki summit with Russian President Vladimir Putin.

"At this point there is certainly enough there for the case to proceed," O'Rourke said, according to the Dallas Morning News.

But Cruz's camp noted that O'Rourke was "the only major party candidate in America" to take an impeachment stand.

"Elizabeth Warren hasn’t done it. Bernie Sanders hasn’t done it. Nancy Pelosi hasn’t done it. This is a fringe candidate in the Democratic Party,” Jeff Roe, Cruz's campaign manager, told the newspaper.

Since April 1, 2017, O’Rourke has raised $23.1 million, compared to Cruz’s $12.9 million, the Dallas Morning News reported.

Overall, however, Cruz still has a slight advantage – having raised a total of $25.9 million since late 2012, according to the paper.

The combined total for the two candidates has reached nearly $50 million, with nearly half of that total already spent, making their race by far the most expensive U.S. Senate campaign in the country, the Houston Chronicle reported.

Cruz has surpassed the fundraising totals for any other Republican seeking a Senate seat, while U.S. Sen. Elizabeth Warren of Massachusetts has raised the most of any Democrat, with nearly $27 million available for her re-election bid, the Chronicle reported.

Warren is just one of several Democrats believed to be interested in making a presidential run in 2020.

With November's midterm elections nearing, O’Rourke currently holds a cash advantage over Cruz, with reserves of just under $14 million compared to about $10.2 million for Cruz, the Morning News reported.

However, O’Rourke still struggles with name recognition in parts of Texas, the paper notes, while Cruz, who is seeking his second term, is well-known across the state -- and in Washington.

With Democrats making a heavy push to regain control of the House of Representatives, Cruz is not taking re-election for granted, as evidenced by a recent comment.

“The news is BAD. VERY BAD.... We need to step up," Cruz said, urging donors to contribute to his campaign as O'Rourke's fundraising numbers continue to rise, the Morning News reported.

"No doubt we have been outraised this year because the far left is very engaged in this election," Emily Miller, a spokeswoman for the Cruz campaign said last week, according to the paper. "Some will see the polls and fundraising numbers as reason for alarm, while others see them as a wake-up call to voters who are being too complacent going into midterms. Either way, we are making sure that Texans who value freedom will know the current stakes."

Cruz currently holds about an 8 percentage point lead over O’Rourke, which is relatively low compared to his 16 percentage point margin of victory in 2012 and for a state that hasn’t elected a Democrat since 1994, according to the Morning News.

Despite O’Rourke’s push to be a legitimate contender in November, Cruz is still considered the favorite – but that could change in the coming months.

Democrats need to win 28 seats to control the Senate, compared to only 9 for Republicans, the New York Times reported. As for the House, Democrats need to flip 24 Republican-held seats.