People listen to a Donald Trump speech in an overflow room during a campaign event Jan. 23 in Pella, Iowa. Getty Images

After a dramatic caucus night in Iowa ended Monday with wins for Republican Sen. Ted Cruz of Texas and (barely) Democratic former Secretary of State Hillary Clinton, some observers are starting to consider who might serve as the winners' vice presidential picks if they do eventually secure their parties' nominations.

While Donald Trump, the Republican front-runner in the polls, had been touting his large fan base in Iowa, the real estate mogul was eclipsed by Cruz, who took 27.7 percent of the vote to his 24.3 percent, with Florida Sen. Marco Rubio a close third, the Associated Press reported. If Cruz wins the nomination, here are a few potential picks for his running mate.

John Kasich: The popular Ohio governor and Republican presidential candidate has often been overshadowed by the media antics of Trump and others. He offers a balanced perspective, according to a voter survey in the New York Times, and would serve as a counterpoint to the more conservative Cruz. Ohio is also a big swing state with important electoral votes, and his presence on the ticket would boost Republican chances there.

Nikki Haley: The South Carolina governor was tapped to give the Republican Party's response to President Barack Obama's State of the Union address in January — a prestige spot that signaled her party's respect for her as a politician, the Washington Times reported. As a woman and the daughter of Indian immigrants, Haley might also help Republicans with minority groups and women voters.

Carly Fiorina: While the former HP CEO has said she is not interested in serving as vice president, her support as a presidential candidate has dropped steadily in the past several months. Coming from the private sector, Fiorina would offer a counterpoint to the Texas senator, a lawyer, and she may play well with women voters.

Favorability Ratings of GOP Candidates | InsideGov

On the Democratic side, Clinton won the Iowa caucus by only 0.3 percent, in a victory that rival Sen. Bernie Sanders from Vermont has contested. Clinton finished with 49.9 percent and Sanders with 49.6 percent. If Clinton takes the Democratic nomination, her camp has several options to consider.

Julián Castro: The 41-year-old former mayor of San Antonio has long been discussed as a potential running mate for Clinton, given his presumed appeal to young voters and Latino communities. "It would be a balanced and diverse ticket, and it would be two firsts: a female as president and a Latino as vice president. I think it’s a better reflection of America than what the other side can offer,” said Rep. Lacy Clay, D-Mo., a Clinton supporter, the Hill reported.

Martin O'Malley: The former Maryland governor and former mayor of Baltimore won 0.4 percent of the votes in Iowa Monday, and dropped out of the race. O’Malley has largely treated the former secretary of state with respect and did not harp on Clinton’s email scandals in the campaign. "I believe that now that we're finally having debates, Anderson [Cooper], that we don't have to be defined by the email scandal, and how long — what the FBI's asking about," he told CNN in an interview.

Elizabeth Warren : The popular Massachusetts senator has often butted heads with Clinton, though her more aggressive approach on issues such as regulating Wall Street could win over progressives. A two-woman ticket may alienate male voters, however, pundits have warned.