In a capital city defined by its cutthroat politics, no commodity is more precious than loyalty. That's especially true in Clintonworld, where every favor and every slight is carefully tracked.

And it helps explain why scores of federal workers, including several members of Congress, would make maximum contributions of $2,700 to Hillary Clinton's campaign. The donations won't buy jobs in the West Wing, but they are a time-honored way for Washington's most ambitious players to prove their loyalty to the person they think will be the next president of the United States. And the earlier they give, the better.

Take, for example, Tony Blinken and Evan Ryan, who are married to each other. He's a deputy secretary of state; she's an assistant secretary of state. They both donated to Clinton in late June, just before the most recent deadline for campaigns to file finance reports with the Federal Election Commission. Given the tradition of giving for political gain, it's not surprising that one of the rare true power couples would part with a total of $5,400.

It's really a small investment when you think about it. Blinken could be in line for any number of jobs in a Clinton administration, including the one he has, secretary of state, or national security adviser to the president. Ryan would certainly be under consideration for at least an undersecretary post at State or perhaps a high-ranking White House job.

What's surprising about their contributions to Clinton is that Blinken and Ryan couldn't be much closer to Vice President Joe Biden, who hasn't said yet whether he will seek the Democratic presidential nomination in 2016. Blinken was a top aide to Biden on Capitol Hill and the vice president's national security adviser. Ryan handled intergovernmental affairs for Biden at the White House. Both of them moved over to State after Clinton left. The facile read — and one we admit was our first thought — is that they just unintentionally signaled that Biden won't run.

But Blinken and Ryan are too smart for that. After all, he plays the 195-dimensional chess of international politics for a living, and she's one of the more capable unelected politicians in Washington. Blinken declined to comment for this story, but it doesn't take much training in game theory to figure out his basic incentive structure and the optimal choice.

In Washington's unwritten code of loyalty ethics, it would be perfectly appropriate for Blinken to support Biden if his former boss made the surprise decision to run. Clinton could forgive him for owing greater loyalty to just one person — perhaps even find that decision honorable — and look at his early donation to her as a sign that he likes both of them.

Not all of the 200-plus federal workers who gave to Clinton — a group that poured at least $350,000 into her coffers — have the same kind of incentives for giving. Dozens of them gave $250 or less. The set includes Air Force pilots and a midlevel US Forest Service employee. As a point of comparison, 18 federal workers, including Sen. Susan Collins (R-ME) gave a total of a little more than $15,000 to Jeb Bush in his first fundraising quarter. The data only include those who gave $200 or more to Clinton or Bush, because that's the threshold at which campaigns are required to itemize the names and occupations of contributors.

For top political appointees who would like to keep working in the next administration, writing a big check is an obvious call. Clinton's givers include Health and Human Services Secretary Sylvia Burwell (who listed herself as a "manager" at her department), Deputy Labor Secretary Christopher Lu, and US Treasurer Rosie Rios. Lu and Rios owe their positions to their work for Obama. Burwell's case is a little different: She was a deputy director of the Office of Management and Budget during the Clinton administration and has risen through the upper echelon of the executive branch under Obama.

Making up is easy to do. Just write a personal check.

During the 2008 campaign, there was no one more hated in Clintonworld than Sen. Claire McCaskill, a Missouri Democrat. McCaskill had said on Meet the Press in 2006, as she campaigned for the Senate for the first time, that she wouldn't let her daughter alone in a room with Bill Clinton. She tearfully apologized, and the Clintons seemed to forgive, if not forget.

But McCaskill chose to endorse Obama early on in the 2008 race and proceeded to be one of his most vociferous advocates on cable television. The fact that she was a prominent woman so opposed to Clinton was very good for Obama's narrative and very bad for Clinton's. The Clinton operation ranked her as a 7 on a spreadsheet of members of Congress rated 1 through 7, with the lower numbers indicating a high level of loyalty and the higher numbers showing the greatest perceived treachery.

She was dead to them.

Then, around the time Clinton left the State Department, McCaskill endorsed her for president in 2016. When the story failed to get much national attention, she reendorsed Clinton. She went to a Clinton Global Initiative summit in Missouri. And then when Clinton started raising money for the presidential campaign, McCaskill wrote a personal check for $2,700. While dozens of Democrats donated from their campaign accounts, McCaskill's personal contribution is an even stronger show of allegiance.

She's not the only one: A half-dozen Democratic lawmakers gave from their own pockets. Rep. Earl Blumenauer (D-OR) endorsed Obama in February of 2008; now he's a Clinton donor. Rep. Don Beyer, who campaigned for Obama and became an ambassador in his first term, also wrote a personal check. Colorado Rep. Jared Polis, then running for the first time, backed Obama in April 2008. He, too, ponied up for Clinton last quarter. Obama cut an ad for Rep. Jim Himes, then running for the first time, in 2008. You guessed it: He's an early Clinton supporter this time around.

There's one longtime Clinton backer in the mix of lawmaker donations, too: Rep. Bonnie Watson Coleman, a member of the Congressional Black Caucus, endorsed Clinton in 2008, when Coleman was the state Assembly majority leader.

In Washington, nothing says "I love you" like a $2,700 check.