On Thursday, former Democratic Congressman Beto O’Rourke announced he was running for president. O’Rourke made a big enough splash for President Trump to find a way to insult him, which suggests that it’s not wildly inappropriate for him to run.

It would have seemed a bit inappropriate just a few years ago, however. O'Rourke has some local government experience, three terms as a U.S. representative, and a splashy but ultimately unsuccessful Senate campaign against one of the most unpopular politicians in America. To put this in another, more cruel way: Beto O'Rourke has less executive experience than Sarah Palin and less government experience than Dan Quayle when they ran for vice president.

Furthermore, some prominent Democrats wanted O'Rourke to run for a different office and challenge Republican John Cornyn for his U.S. Senate seat. Indeed, O'Rourke is merely the latest potential recruit of Senate Minority Leader Charles Schumer, D-N.Y., to decide to run for president rather than a Senate seat in 2020. Former Colorado Gov. John Hickenlooper also spurned Schumer and chose to run for president rather than challenge Sen. Cory Gardner. Indeed, Hickenlooper went out of his way to say, "I'm not cut out to be a senator," last month.

And then there is Stacey Abrams, who pulled off unprecedented double feat of writing an interesting Foreign Affairs essay and delivering a dynamic State of the Union response. After losing narrowly in the Georgia governor's race last November, Schumer has tried to persuade her to run against Georgia Sen. David Perdue, R. At South by Southwest, however, Abrams talked about running for president. She later tweeted, "Now 2020 is definitely on the table." Former Montana Gov. Steve Bullock is also aiming at the presidency rather than Steve Daines's Senate seat.

Both Politico and the New York Times have noted the phenomenon of presidential campaigns crowding out possible Senate campaigns. The NYT's Glenn Thrush writes, "The Democratic Party's bench is shallow in states that have been dominated by Republicans, like Georgia, Montana, North Carolina and Texas. It is rare for the party to have first-class candidates in such states, let alone talents like Ms. Abrams, Mr. Bullock and Mr. O'Rourke. And getting them to stay at home has proved nearly impossible." It is possible that some of these candidates might try to pull a Rubio if they don't secure the nomination, but one wonders if that option is available only to incumbents.

This seems like an odd trend. Sure, Trump is unpopular, but the fundamentals of 2020 would still seem to favor the incumbent for now. The economy looks pretty good, and Howard Schultz seems bound and determined to complicate life for the 2020 Democratic Party nominee as a potential independent candidate. On the other hand, an awful lot of suburbanites in Texas, Georgia, and Colorado who gave the House to the Democrats might be inclined to vote for a Democrat in the Senate. So what can we make of this phenomenon?

One possible explanation is that the fundamentals are trending in the wrong direction for Trump. Even with a strong economy, he is a very vulnerable candidate. Simply put, there is little chance of Trump winning any of the states that Hillary Clinton won in 2016, and 2018 delivered results in Iowa, Michigan, Pennsylvania, and Wisconsin that should scare the crap out of his reelection campaign.

Another factor to consider is that Trump himself has seriously lowered the barriers to entry to running for president. In getting elected, Trump demonstrated the existence of a pathway to the highest office in the land that does not require years in the Senate to build out a resume. Furthermore, the very surfeit of candidates increases the likelihood of an outlier winning the race. As 538′s Nate Silver pointed out last month, "The three past elections when the field was as large as its shaping up to be in 2020 all resulted in party elites failing to get their way."

My hunch, however, is that the biggest explanation is the simplest: It's better to be the president than a senator. Sure, senators have longer terms of office, but they also don't have much individual power. That is particularly true in a polarized chamber in which partisanship matters more than anything. In January, Hickenlooper told Colorado Public Radio, "As a senator, most senators don't - you don't become even the vice chair of a reasonably important committee until your third term... But by the time I got to my third term, I'd be eighty." This is an exaggeration, but not an outrageous one. One reason Barack Obama ran for president after serving only two years as a Senator was that he was frustrated by his lack of influence and the "glacial pace" of the chamber.

Meanwhile, even a fundamentally weak man like Trump can still get a few things done as president of the United States. Imagine what someone with actual political experience, like Hickenlooper, Abrams or O'Rourke, could do if they won the presidency. Even without a pliant Congress, the president can do an awful lot.

This suggests that there's a really good reason to empower Congress a bit more; it might attract a better crop of candidates.