There’s an old saying in the nation’s capital that "every senator looks in the mirror and sees a president," but that doesn’t appear to be the case right now in the hunt for the GOP nomination. 

Sen. Tim Scott of South Carolina is sending plenty of 2024 signals, as the only Black Republican in the Senate is kicking off a listening tour this month, heading to Iowa, and going up with digital ads in the state that kicks off the GOP presidential nominating calendar, as Fox News first reported earlier this week.

But Scott appears to be in a league of his own, as his Republican colleagues in the Senate whom political pundits have viewed as potential 2024 presidential contenders are staying on the sidelines as of now.

Sen. Ted Cruz of Texas, the runner-up to former President Donald Trump in the 2016 GOP presidential nomination slugfest, has not ruled out another White House run in 2024, but told Fox News in November that "I’m fighting in the Senate. I’m running for re-election in the Senate. I’m focused on the battles in the United States Senate."

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Sens. Marco Rubio of Florida and Rand Paul of Kentucky, 2016 Republican nomination contenders who overwhelmingly won their 2022 Senate re-elections, are making no noise about tangling with Trump again, as the former president runs a third time for the White House.

Sen. Tom Cotton of Arkansas, another rising star in the GOP who had traveled extensively to the early voting states of Iowa and New Hampshire the past two years, announced just ahead of November’s midterms that he was passing on a 2024 presidential run. 

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"This is not the right time for our family for me to commit to a six-to-seven day a week campaign for the next two years," Cotton told Fox News Digital.

Another conservative senator whom political prognosticators viewed as a potential White House contender — Sen. Josh Hawley of Missouri — reiterated soon after the midterms that he had his eyes on his 2024 re-election bid rather than a White House race.

Sen. Joni Ernst of Iowa’s name has also come up in 2024 conversations, but she’s repeatedly said there’s "zero" chance she’d run for president this cycle.

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The reasons senators are sitting out the 2024 presidential fight could be Trump, who launched his campaign in mid-November, and Florida Gov. Ron DeSantis — the conservative firebrand whose popularity has soared among those on the right the past couple of years, and whom pundits view as a likely presidential contender. Trump and DeSantis are grabbing outsized attention and are the two front-runners in early 2024 GOP nomination polling.

Longtime New Hampshire based national Republican consultant David Carney noted that if DeSantis ends up launching a campaign later this year, "it takes a lot of the oxygen out of the air" for others potential contenders.

Carney, a veteran of numerous Republican presidential campaigns the past couple of decades, said a race with both Trump and DeSantis would "make the math very difficult" for other hopefuls.

The previous two open presidential nomination races — for the Democrats in the 2020 cycle and the Republicans four years earlier — launched relatively early and attracted plenty of candidates. But no one’s expecting a very large field like the 17 Republicans who ran in the 2016 presidential cycle, or the 27 Democrats who ran in 2020.

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"Right now, the field is a bit frozen, compared to the last two primaries," noted Republican strategist Jesse Hunt, a longtime communicator who worked for the Republican Governors Association, the National Republican Senatorial Committee, and the National Republican Congressional Committee the past couple of cycles.

Pointing to Trump and DeSantis, Hunt said "they’ve certainly received outsized attention early on," and that "could certainly be a factor on what these senators ultimately decide."

Hunt, a veteran of presidential campaigns also pointed out that some of these senators who are currently sitting things out in the 2024 race — unlike governors — "have the benefit of being in touch with the national press corps on a near daily basis" due to their day jobs in the nation’s capital.

Age may be another consideration.

Paul is 60. Cruz, Rubio and Ernst are in their early fifties. And Cotton and Hawley are in their early forties.

"All these people are young in political years," Carney observed.

And pointing to Cruz, Rubio, and Paul, Carney cautioned that "running a second time and not doing well is the end of you."