What did Donald Trump do today?

He used the presidency as a prop.

Today, Trump used the White House and the powers of the presidency itself as a prop in at least five different ways as part of the virtual substitute "convention" the RNC is airing this week. In one taped segment, Trump issued a pardon—supposedly as a "surprise," which if true, would mean the recipient was unaware he was taking part in a political ad. In another segment, Trump attended a naturalization ceremony in the White House. He had his Secretary of State, Mike Pompeo, deliver a campaign speech praising Trump's foreign policy from Jerusalem, where he was on official business. And his wife, Melania Trump, delivered a similar speech from the Rose Garden of the White House, which is not part of the first family's residence, where political activities are allowed. Trump also put Marines in dress uniforms as part of the backdrop for some taped segments.

It's illegal to use the powers of a federal office, or government property, or authority over military personnel, for political purposes. There are a number of anti-corruption laws that address this, but the main one is the Hatch Act of 1939. It doesn't apply to the president or the vice-president, but that doesn't mean that—for example—a president could rent out the White House to raise money for a re-election campaign. It would just mean that the people breaking the law wouldn't be the president. 

For example, Pompeo's own State Department issued a memo last December barring him—or other high-ranking political appointees—from even attending a convention, much less endorsing a candidate as part of their official duties.

Why does this matter?

• Using the privileges of office for personal gain is pretty much the definition of corruption.

• The president is supposed to serve the government of the people, not the other way around.

• It's bad if the only time a president seems interested in doing his job is when it can benefit him personally.