(CNN) - Democrats on Capitol Hill have a message for presidential hopefuls John Hickenlooper, the former governor of Colorado, and Steve Bullock, the current governor of Montana: you'd make great senators.
Hickenlooper and Bullock have struggled to gain traction in a crowded field of Democratic presidential candidates, but as governors, they have already proven they can be elected statewide. As Democrats gear up for a fight for the Senate, many are quick to say they believe Hickenlooper and Bullock would make formidable challengers to Republican senators up for re-election in Colorado and Montana.
"I would urge them to think about this moment in our history and what would be best for the country," Democratic Sen. Martin Heinrich of New Mexico told CNN of Hickenlooper and Bullock, saying "no doubt about it," when asked if he thinks they would make strong Senate candidates and adding that he believes they would make good senators.
All eyes may be on the 2020 presidential election -- particularly during the week of a second series of debates in Detroit hosted by CNN -- but the stakes are high in the fight to control the Senate. If Democrats win the White House, it would be virtually impossible for the party to enact a sweeping liberal agenda if Republicans retain the upper chamber. If President Donald Trump wins a second term, Democratic control of the Senate would give the party the ability to block Republican priorities like the confirmation of conservative judges.
As Hickenlooper and Bullock campaign for the White House, neither seems interested in abandoning their presidential bids for a Senate run, and both have publicly dismissed the idea. Hickenlooper has said that he is "100% focused" on his presidential campaign, while Bullock has said repeatedly that he has ruled out a Senate run.
National Democrats appear to be choosing their words carefully. Hickenlooper and Bullock will have to decide for themselves what the future holds, they emphasize, and they aren't going as far as to say they hope either one ends their presidential bid.
"We would certainly love to have them. They're incredibly bright and accomplished, successful public servants, but they have to make their own decision," Michigan Sen. Debbie Stabenow told reporters on Capitol Hill when asked recently about Hickenlooper and Bullock.
'There's going to be a winnowing'
The fight for the Senate is already underway and Democrats have recruited a number of challengers generating attention and bringing in money across a series of battleground states.
In Maine, a state that Hillary Clinton won in 2016, Sara Gideon, the Maine Democratic House speaker, has launched a high-profile challenge to Republican Sen. Susan Collins. In Arizona, former astronaut Mark Kelly, the husband of gun control advocate and former Rep. Gabby Giffords, is challenging Republican Sen. Martha McSally. Those, along with others, are shaping up to be some of the most closely watched Senate races.
National Democrats say they're excited by the current field of Democratic Senate recruits, but that hasn't stopped them from thinking about the possibility that some presidential candidates might also throw their hats into the ring.
Democratic Sen. Tim Kaine of Virginia believes that Democrats have "a number of very solid recruits," but said, "I think there are still some folks running for president that we hope might decide they want to run for the Senate."
"I do think there's going to be a winnowing down of the field and some of the folks who are out there right now I think would be good Senate candidates so I hope some of them may reassess," Kaine added, though he didn't name any particular candidate.
There are other presidential candidates who could opt to run for a Senate seat if they were to exit the presidential race, including former Texas Democratic Rep. Beto O'Rourke, who unsuccessfully challenged Republican Sen. Ted Cruz in 2018 in a close race. Republican Sen. John Cornyn is up for re-election in Texas in 2020. Several Democratic challengers have emerged in that race, including Air Force veteran M.J. Hegar.
Democrats say there's still time
Some Democrats say there's still time for Hickenlooper and Bullock to jump into a Senate race -- that is if they wanted to.
"They're both extremely well known. Any one in a position of such high respect that's well known has time," Stabenow said, pointing out that the 2020 Senate primaries in Colorado and Montana won't take place until next year.
Some Democrats point out that as time passes, it could become more complicated to launch a Senate bid.
Sen. Dick Durbin of Illinois, who as minority whip is the No. 2 Democat in the chamber, told CNN, "I think the options get more complicated because there are others in the field who aren't going to wait on them," when asked if the window is closing for Hickenlooper and Bullock to jump into a Senate race.
"On paper they're very strong candidates," Durbin said, but he noted, "They should only run if they want to run."
"We'll see how it goes with their 2020 prospects," Democratic Sen. Doug Jones, who faces his own tough re-election fight in the deep red state of Alabama, told CNN. "At least right now there's a fair amount of time, but I think the longer it goes, you worry about getting tagged in the wrong way."
"So hopefully they'll make these decisions, what they think is in the best interest for them and their states," Jones said, adding that Hickenlooper and Bullock would be "very, very strong Senate candidates."
State-level dynamics in Colorado and Montana
Colorado is the other state that Clinton won in 2016 where Democrats have a chance to take down a Republican incumbent -- and Democrats believe they have strong odds of flipping the Senate seat.
There is already a crowded field of Democratic challengers vying to take on Republican Sen. Cory Gardner including: Mike Johnston, a former state senator who reported raising $1.8 million in the first quarter for his Senate run, former Colorado House Speaker Andrew Romanoff and former ambassador Dan Baer.
Peter Cunningham, the communications director for the Hickenlooper presidential campaign, told CNN that Hickenlooper "believes there are several highly qualified Democratic candidates who can beat Cory Gardner."
But that doesn't mean some Democrats aren't still hoping that Hickenlooper will get into the race.
"There's not a day that goes by that someone doesn't ask me about Hickenlooper running," Colorado Democratic strategist Steve Welchert told CNN.
A DSCC official noted that Gardner failed to win more than 50% of the vote in 2014 in a wave election year for Republicans, and that existing Democratic primary candidates in Colorado have already turned in competitive fundraising numbers, demonstrating support and enthusiasm for Democrats in the race.
The official also noted that there are a number of Republican-held Senate seats that Democrats are targeting in 2020 where the terrain will be far more favorable to the party than Montana such as in Arizona, North Carolina, Maine and Iowa as well as Colorado.
Unlike the purple state of Colorado, Montana is a red, heavily conservative state, though it has shown a willingness to elect Democrats to serve as governor and in Congress.
A Senate race in Montana would be difficult terrain for any Democrat, but Bullock has a track record of success with voters in the state. It's not clear that any other Democrat would have the same ability to make the race competitive and potentially flip the seat.
The Democratic bench in Montana is not nearly as deep as it is in Colorado, but so far two Democrats have announced what are widely viewed as long-shot bids to unseat Republican Sen. Steve Daines, including Helena mayor Wilmot Collins, though more candidates may still enter the race.
"Steve has great name ID, really good poll numbers, an operation, a fundraising network," said Barrett Kaiser, a Montana Democratic strategist. "There are sure many of us who would love Steve Bullock to run for the US Senate, but it just ain't happening."
Hickenlooper and Bullock to appear in second primary debate
Hickenlooper and Bullock will take part in the second round of presidential primary debates in Detroit this week hosted by CNN, giving them a national platform and a chance to have a breakout moment, but their campaigns have already experienced setbacks.
Hickenlooper polled at less than 1% among registered voters who are Democrats or Democratic-leaning independents, while Bullock polled at 0% in CNN's most recent national poll of the Democratic presidential field conducted at the end of June after the first presidential debate.
Bullock failed to qualify for the first debate after getting into the race later than many of the other Democratic presidential candidates. The Montana governor jumped into the race in mid-May, and raised $2 million for his presidential bid in a month and a half for the second quarter of 2019.
Hickenlooper launched his presidential campaign a few months earlier in March and did make it onto the first presidential debate stage. The former Colorado governor is now past the point at which a campaign might experience an initial fundraising boost and raised around $1.1 million in the second quarter.
It's unclear whether either will make it to the third round of debates in September where the threshold to qualify will be higher.
If they don't make the cut for that debate, the calls to consider a Senate run may grow louder.
The pressure to consider a Senate run isn't just coming from Democrats in Washington: A group of senior aides to Hickenlooper's presidential campaign urged him to end his bid for the Democratic nomination and run for Senate last month, multiple sources familiar with the discussion told CNN.
What it's like to go from governor to senator
Hickenlooper and Bullock have both talked about how as governors they are used to serving as executives, not as part of a legislative body with a reputation for gridlock.
Against that backdrop, some Senate Democrats are making the case that going from governor to senator can be a rewarding experience.
When asked specifically about Hickenlooper and Bullock, Kaine, who formerly served as Virginia governor, argued that the ability to work on diplomacy and national security is a rewarding experience that governors don't get to have.
"The opportunity that I think sometimes governors don't understand about the Senate is both the intellectual challenge, but also the deep patriotic satisfaction that comes with working on national security issues," Kaine told CNN, adding, "That's a message we need to convey to some folks."
Some Democrats insist, though, that even if Hickenlooper and Bullock aren't running for Senate, that doesn't bother the party.
"No, no, I don't think there's a sense of frustration," said Democratic Sen. Ben Cardin of Maryland.
"Obviously we want to get the best candidates in all of our states," Cardin said, "but we're very pleased where we are."
By Clare Foran, CNN
™ & © 2019 Cable News Network, Inc., a Time Warner Company. All rights reserved.
for more features.