One of the biggest political sub-plots coming out of the early part of 2016 was the feud between Donald Trump and Texas Sen. Ted Cruz. While it appeared that the Trump-Cruz fiasco was in the rear view mirror, the battle doesn't appear to be over just yet.

Trump vs Cruz: Round 2

The feud between the two candidates reached a fever pitch when the National Enquirer released a story claiming that Cruz had been having an affair with at least five women other than his wife. Trump pounded on the story, using it as leverage against the senator from the Lone Star State.

After Trump picked up enough delegates to secure the nomination last month, Cruz, along with Ohio Gov. John Kasich, dropped out of the race, but refused to offer his endorsement on his way out. With the Republican convention just a month away, Trump is doing whatever he can to prevent Cruz and Kasich from appearing, as reported by The Hill on June 26.

"If there's no endorsement, then I would not invite them to speak," Trump said during an interview with The New York Times. The former host of "The Apprentice" has drawn a line in the sand, attempting to block his former rivals as the in-fighting in the GOP only continues to grow.

Trump was also asked about the "Never Trump" movement, including Republican delegates and candidates who are actively pursuing ways to replace him as the party's nominee.

"You mean to tell me we're going to get the largest vote in his history of the Republican primaries and now the same people that either didn't run or get beaten in a landslide are going to try and back-end?" Trump shockingly told the paper in amazement.

According to Republican National Convention rules, Cruz can't be blocked by Trump from speaking at the convention due to picking up the majority of delegates in over eight primary states.

Election forecast

Just one month ago, Trump had narrowed the gap against likely Democratic nominee Hillary Clinton. In some nationalelection surveys, Trump and Clinton were polling even within the margin of error.

Due to recent slip-ups by his campaign, Trump has fallen behind the former Secretary of State, trailing by seven points in the latest Real Clear Politics rolling average. With the Trump University fraud case set to begin later this month, and the Democratic primary ending in just four weeks, Trump will be forced to make-up ground as quick as possible if he plans to have a realistic shot at the White House in November.