Ahh, the ebbs and flows of a presidential campaign.

One day the polls say you have zero chance of winning, the next day you’re holding a slim lead.

So goes the battle between Hillary Clinton and Donald Trump.

The FBI investigation, the drama of picking a VP, which according to several sources is going to be Indiana Governor Mike Pence, and the many surrogates working hard to flood the airwaves with their talking points and finely coiffed hair and suits. It’s all very important and possibly game-changing stuff, but the larger question remains.

What is Donald J. Trump’s ceiling?

If you ask Paul Begala, Hillary Clinton’s super PAC strategist, he’ll tell you Trump's ceiling is right around 40%, which is where both candidates are currently polling. Why is that important? A candidate will likely need close to 50% to win the White House. That equates to about 65 to 70 million votes.

Begala is working hard to keep Trump as close to 40% as he can, “With Trump, he wants to build a wall; I want to build a ceiling. Right now he’s got his 40 percent of the vote and it is ironclad. I want to build a ceiling. We’ve been advertising very heavily on the outrageous things that Donald Trump has said about women, about national security, most powerfully about the disabled and that is building a ceiling. There is only one national poll out of ten or twelve that has him even over 40 and he has got to get close to 50.”

Trump was able to reach the 50% mark in late April and with the selection of his VP candidate Pence, he could begin to forge a lead over Mrs. Clinton nationally.

There’s also this. The Black Lives Matter movement could actually HELP Trump’s candidacy.

The decision by leaders of the BLM to continue protests even after five white police officers were shot and killed in Dallas gave Trump a golden opportunity. Trump seized on it and has now labeled himself the “law and order” candidate. With violence and disorder erupting nearly every week across the country, it could become harder and harder for a majority of Americans to turn their back on the “law and order” candidate.

Additionally, a new Pew poll shows Evangelicals rushing to Trump’s side. Seventy-eight percent of white evangelical voters say they would vote for Trump if the election were held today, including about a third who “strongly” back his campaign.

All of this could mean a ceiling of closer to 55% nationally for America’s ultimate showman.

Still to be determined, though, is what impact, if any, Libertarian presidential nominee Gary Johnson could have on the race. The latest poll shows Johnson at 12% nationally, up from 10% just two months ago. If Johnson continues to climb and makes it into the national conversation and debates, he could very well have a big impact on the outcome.

But this is mid-July, and with the election still months away, anything, as we have seen in this campaign, is possible.