While conventional wisdom holds that Donald Trump will be a drag on Republican chances of maintaining control of the House, those vying to expand the party’s majority in the Senate are embracing the president as a unique asset in the upcoming campaigns.

Unlike the House map, the Republicans' path to success in the upper chamber runs through 10 states Trump won in 2016 -- five of them by double-digit margins. But beyond those favorable fundamentals, the GOP is looking to the president to lead something of a mass-marketing campaign against well-known Democratic incumbents.

Party operatives see the president's penchant for coining catchy -- and pejorative – nicknames, along with his made-for-television campaign rallies, as particularly helpful through the long primary process, helping to define the opposition while Republicans pick their nominees.

"The messaging power and the branding power Trump has is different from any elected official," said one Republican familiar with Senate races this year. "It's a very valuable asset he has, and that he alone has been able to hone."

Despite the party’s favorable map, Majority Leader Mitch McConnell has cautioned Republicans not to "fall in love" with it. Most of the Democratic incumbents in the 10 so-called Trump states are battle-tested, well financed and have made names for themselves as independent of the national Democratic Party and as officeholders in sync with their electorate. And in some of those states, Republicans have yet to field a credible challenger.

But the GOP is counting on the president to spotlight the incumbents’ votes, particularly on the tax reform bill. Strategists point to Vice President Mike Pence's trip to West Virginia last week as an example of what is to come from the top. There, he hit Sen. Joe Manchin for voting against the tax bill, health care repeal and other Republican priorities, repeating the phrase "Joe Voted No" and following up later with a series of tweets. Manchin fired back, defending his votes and calling Pence divisive and partisan.

On Tuesday, the two-term senator unveiled a pledge that he encouraged his fellow Democrats to sign, saying they would not campaign against their sitting colleagues. The move was seen as an attempt to bolster his bipartisan brand, but it also signaled his own vulnerabilities in this environment. West Virginia gives Trump his highest approval ratings, even though Manchin registers even higher numbers in a state the president won by 42 percentage points.

Trump has yet to attack Manchin at political rallies or on Twitter. But Republicans expect that to change. They point to an interview the president gave to the New York Times in December in which he expressed his frustration with Democrats. "He talks. But he doesn’t do anything. He doesn’t do,” Trump said of Manchin.

"The thing the president does best are these big, huge rallies, and that could be tremendously helpful," said Rob Jesmer, former executive director of the National Republican Senatorial Committee. "He'll go into fertile territory and make the case that these guys didn't do anything with him."

Republicans have already gotten a head start in some of their challenges to Democratic incumbents, but hope Trump will amplify their messaging. They have called Indiana’s Joe Donnelly "Mexico Joe," for example, referring to reports that the senator's family business outsourced jobs.

Trump can "define those senators to audiences that are clearly receptive to his style and message," said Alex Smith, executive director of the America Rising PAC.

In addition to Indiana and West Virginia, Democrats must defend seats in the deep-red states of Missouri, Montana, and North Dakota. They also must protect incumbents in five purple states the president won: Florida, Michigan, Ohio, Pennsylvania, and Wisconsin.

"The Senate map is in states where the voters are very happy with the Trump administration," noted GOP strategist Brad Todd. "You can't replace the value of the bully pulpit and megaphone that happens when Air Force One comes to your state."

Still, significant challenges for the party remain. For starters, it hasn’t yet fielded a candidate to run against Heidi Heitkamp in North Dakota, which Trump won by 36 points. At-large Rep. Kevin Cramer recently passed on a run. And Trump's hold on some of these states varies. For example, he only won Michigan, Wisconsin and Pennsylvania by a point or two. And Montana is accustomed to ticket splitting. In 2016, for example, voters backed Trump but also re-elected their Democratic governor, Steve Bullock.

And while Republicans see Trump as an effective messenger and mobilizer, he is also notoriously prone to veering off message. During a stop Monday in Ohio, where he was slated to tout the tax law, Trump criticized Democrats for not applauding his State of the Union Address. "They were like death. And un-American. Un-American," he said. "Somebody said 'treasonous.' I mean, yeah, I guess, why not? Can we call that treason? Why not? They certainly didn't seem to love our country very much."

The comments figured to further alienate Democrats he will need to pass remaining items on his agenda, given the GOP’s slim 51-seat majority in the upper chamber.

Republicans will have to defend a couple of competitive seats of their own in Arizona and Nevada. And Democrats are making a play for Texas -- which will, at the very least, force Republicans to spend money in a reliably red state. Arizona has a crowded GOP primary that runs through August, giving Democrat Kyrsten Sinema ample time to make her case. Hillary Clinton won Nevada, where Sen. Dean Heller is facing a primary challenger. Democrats recruited Rep. Jacky Rosen to run there, and she is well positioned.

Additionally, it's not clear that Trump can transfer his support down the ballot. He struck out twice in Alabama after endorsing and campaigning there.

"You still have to run your own race," said Jesmer. "Nationally there will be a GOP headwind, and even in these states, they need to be smart about it."

But Republicans say they are heartened by strong signs of voter endearment to Trump in those states. In Arizona, Sen. Jeff Flake admitted he couldn't win a primary with his anti-Trump views. Rep. Martha McSally is considered the GOP establishment choice for the nomination, but she has evoked Trump’s language when talking about immigration. On Tuesday, she attended a meeting at the White House and issued a photo of herself sitting with the president. And while Heller is considered the most vulnerable Republican running for re-election in the Senate, he voted in favor of repealing Obamacare and for the tax bill, even standing behind the president at a White House ceremony.

"In Republican primaries, normally the play is about who can out-conservative who. But the way they are playing out now is, who is closest to President Trump, and that's something different than before," said the GOP operative familiar with Senate races.

Republicans also figure that their candidates are going to be tied to the president anyway, so they might as well benefit from it, especially if he can turn out voters on their behalf.

"Democrats are going to be heated up whether Donald Trump comes to Missouri or not," said John Hancock, former Missouri GOP chairman. The president "has done a lot of things well in his first year, and if you believe in them you want to go out and embrace him. ... Chart your own course, but don't be afraid to embrace the good things."