By Robert Donachie, Washington Examiner

As President Donald Trump makes his way across the country to stump for Republican candidates in tight Senate races, Republican aides worry that the House of Representatives is being left behind.

In the final days before the midterm elections, Trump is traveling to West Virginia, Indiana, Montana, Florida, Georgia, Ohio, and Missouri to stump for Republican candidates he believes he can give a last-minute boost in the polls.

Focusing on Senate battles appears to be the most effective use of Trump’s time, but his lack of attention to House races in the final days is causing some concern for GOP House staffers who are already preparing for the “blue wave” in the lower chamber.

“I would not write this off entirely as if there is zero chance [of keeping the House]. There is a path and that path is narrow,” a GOP leadership aide told the Washington Examiner Friday from the campaign trail.

“I think if we hold it, it is by a small margin of something like 5 to 8 seats. The last few weeks our side got more energized and closer to the level that we have seen from Democrats all along. I do think that the events of the last week – the Pittsburgh shooting, mail bombs – has been tough for some. I think it is still closer than where we were a month ago.”

Colorado’s 6th Congressional District, where incumbent Republican Mike Coffman faces Democrat Jason Crow, is seen as one of the more likely GOP-held seats to fall to Democrats in this election. The Hill on Friday included the suburban-Denver district among its “Top 10 GOP House seats most likely to flip in a blue wave.”

Trump has not campaigned in Colorado – a state that voted for Hillary Clinton in 2016 – ahead of the election, and when Vice President Mike Pence stopped at a fundraiser in Denver recently, he did not appear with any candidates.

Aides within the more conservative faction of the party do not think the Republican-led House did enough to prove to voters they are worthy of re-electing. Many, like House Freedom Caucus co-founder Jim Jordan, R-Ohio, argue that the accomplishments of this Congress are really attributable to Trump.

“The thought is that the president is obviously working very hard to keep the majority, but at the end of the day there has to be a reason we lose. So if we are going to lose, the reality is that the biggest things that have been done by a united Republican government are all things the president has done. Congress hasn’t done anything exceptional,” one conservative GOP aide told the Washington Examiner.

Some House Republicans argue that they, unlike their Senate colleagues, delivered on a number of promises. The favorite talking point of House Republicans is that they have voted to repeal and replace Obamacare twice since 2015.

One conservative House aide said that while this is true as far as it goes, the Senate has arguably done more for Republican voters by confirming two Supreme Court justices than anything House Republicans have accomplished in the past two years.

“The fact of the matter is that a lot of major policy issues have not been done by Congress. The talking points is that we repealed Obamacare and replaced it and the Senate hasn’t done it,” the aide said.

The president has made this election, much like he did in 2016, about immigration. Night after night, the president is telling voters about the dangers of the caravan of migrants heading to the southern U.S.-Mexico border, which he claims is filled with criminals and terrorists. He decries sanctuary cities, reminds voters of the urgent need for a border wall, and, most recently, floated the idea of striking birthright citizenship from the 14th Amendment.

Republican aides agree that immigration is a winning issue, but that some aspects of the president’s rhetoric, particularly in regards to birthright citizenship, could backfire with suburban voters.

“I think it depends on where you go. I think it [immigration] is a big thing for our base. Not just our base, but voters in general. If you are a mom, you are concerned about the safety of your children. I think the caravan stuff does have an impact,” a House leadership aide said. “On the flip side, with suburban voters, it could have some negative impact.”

The aide added that, “on the whole,” focusing on immigration “is motivating” to the Republican base. They pointed out that “sanctuary cities” and “open borders” are not popular.

Both moderate and conservative Republican aides think there are a few other factors that could boost voter turnout and help them on Election Day. Many aides point to what pundits have described as the “Kavanaugh effect.” The theory is Supreme Court Justice Brett Kavanaugh’s contentious confirmation battle fired up conservative and Republican voters, who viewed the episode as a smear and delay campaign from Senate Democrats.

Republican strategists have told the Washington Examiner in recent weeks they believe keeping the House red is feasible, pointing out that many of the races are within the margin of error. They argue that with some luck and last-minute campaigning, Republicans could see enough of a push to maintain their majority. Many add that Trump’s presence on the trail could help vulnerable House Republicans.

But those working for Republican members in Capitol Hill aren’t buying that. They see their president traveling to states that feature key Senate and fear they’re being left to drown in the blue wave.

Colorado Politics contributed.