Ted Cruz's terrible campaign has backfired and made him one of the most vulnerable senators up for re-election this year.

Sen. Ted Cruz’s (R-TX) desperate bid to hold onto his seat was dealt another blow this week, as he was added to Roll Call’s list of most vulnerable Senate incumbents.

Cruz was elected to the Senate in 2012 by a 16-point margin, and Trump won Texas by 9 points in 2016, but the reliably GOP seat is now in serious jeopardy. In addition to making the Roll Call list, the Cook Political Report recently changed its rating of the Texas Senate race from “likely Republican” to “toss-up.”

Most recent polling shows a race that’s extremely close, and one September poll had Cruz losing for the first time.

Even Trump budget director Mick Mulvaney has admitted that Cruz has a likability problem, but the biggest challenge facing him is the grassroots campaign being mounted by Democratic challenger Rep. Beto O’Rourke.

O’Rourke has been campaigning across every county in Texas and raising enormous amounts of money. Meanwhile, Cruz has been reduced to asking Trump to campaign for him — even after Trump infamously called Cruz “Lyin’ Ted,” alleged that Cruz’s father was involved in the assassination of John F. Kennedy, and even mocked the physical appearance of Cruz’s wife.

O’Rourke’s competitive challenge has prompted increasing desperation from Cruz. In August, Cruz ran a series of attack ads against O’Rourke that included the false suggestion that O’Rourke wants to legalize heroin. The ads backfired, as O’Rourke continued to rake in campaign donations.

When O’Rourke gave a stirring and immensely popular defense of NFL players who protest police violence, Cruz released a video that falsely accused O’Rourke of endorsing flag-burning. But when Cruz tried to echo Trump’s race-baiting attacks on NFL protests, he was promptly booed by a crowd of his own constituents.

Cruz is so desperate that he’s even taken to intimidating and scamming Texas voters, sending out a campaign mailer disguised as an “official summons.”

Cruz should be able to easily win re-election in a state that hasn’t sent a Democrat to the Senate in more than 25 years. Instead, he’s flailing and putting what should be a safe Republican seat in jeopardy.