President Trump and House Speaker Paul D. Ryan (R-Wis.) attend a White House meeting with Republican lawmakers last week. (AP Photo/Evan Vucci)
Opinion writer

The irony is delicious. The candidate so expert in dominating the news cycle and exploiting his base’s unhinged anger is now a drag on his own party — and hence a threat to his presidency — by virtue of those exact same behaviors.

The traditional midterm analysis is that the popularity of the president is the critical factor in determining his party’s prospects. Gallup notes, “In Gallup’s polling history, presidents with job approval ratings below 50% have seen their party lose 37 House seats, on average, in midterm elections. That compares with an average loss of 14 seats when presidents had approval ratings above 50%.” When the president’s approval drops to 40 percent or lower, losses have ranged from a low of 29 seats (in 1950 with Harry S. Truman in the White House) to a high of 55 when he was the incumbent four years earlier.

However, it is fair to say that the anti-Trump reaction may be much stronger given a president whose “strongly disapprove” number is so high and whose base of support is far narrower than the coalition of opposition. Amy Walter of the Cook Political Report puts it this way:

[T]he “all me all the time” messaging is exactly what makes him radioactive in the swing, suburban seats that Republicans need to hold in the House. The more Trump keeps the focus on himself, it means less oxygen and space for issues that are important to these voters; the economy, the Supreme Court and de-regulation.  This is especially true during these last few weeks when the spotlight has been on everything that’s gone/is going wrong with the Trump White House (the New York Times op-ed; the Bob Woodward book; the Manafort/Cohen drama), and very little on what’s going right.

This week underscores the GOP’s dilemma. A week after good jobs numbers (that was just last Friday?!), the top news items include Trump’s insistence that 3,000 casualties don’t mean he messed up the Hurricane Maria recovery; Paul Manafort is looking to flip (an if he doesn’t another batch of convictions may occur before the midterms); another TV executive taken down in the #MeToo era (bad topic for Trump); the ongoing trade wars; and former Environmental Protection Agency administrator Scott Pruitt possibly going to work as a coal lobbyist (you cannot make this stuff up).

Trump and Trump-related scandals, muffs and outrages blanket the news. All of these are salt in the wounds for Democrats and Democratic leaders. Trump’s base is so narrow (thanks to his antics and radical views) and so few persuadable voters will get on board the Trump train at this point that his shtick doesn’t pack the punch it once did. And he won’t go away.

“For the last eight years, Republicans have had effective foils in Obama and Hillary Clinton,” Walter writes. “This year, however, their biggest impediment to keeping control of the Congress is their own party leader. There’s only so much traction that Obama-bashing will get Republicans if Trump remains as unpopular and polarizing as he is right now.” And what’s more, there is a significant segment of the electorate (the Mitt Romney-Hillary Clinton voters) who’d take Barack Obama back if they could (just as there are Democrats who’d take back George W. Bush, if it meant getting rid of Trump).

Finally, the entire GOP argument that if Democrats are elected, the Democrats will investigate corruption, obstruction, his fitness to govern, etc., is getting more nutty by the day. Democrats’ response is increasingly effective: That’s right, it’s about time someone held Trump and his cronies accountable.

Stoking fear that Congress would do its job without spineless Republican majority leaders somehow doesn’t “sing” as a GOP campaign message. And if ever there was a felt need to keep Trump in check, his constant media presence surely will remind voters that an unchecked Trump is a dangerous Trump.