Texas Sen. Ted Cruz accused his Republican presidential rival Donald Trump on Monday of exhibiting inconsistent conservatism and said the billionaire real estate mogul is becoming "rattled" and "dismayed" by his gains. Both Cruz and Trump were campaigning on Monday in New Hampshire, which holds the second contest in the country's primary season. The war of words between Cruz and Trump has intensified in recent days, with Trump going on the offensive over Cruz's eligibility to be on the ballot given his Canadian birth and for Cruz's failure to disclose loans received from Citibank and Goldman Sachs for his 2012 Senate race in Texas. Trump on Sunday called Cruz a "nasty guy" who no one likes. Cruz tried to turn the insult into a joke on Monday, posting a message on Twitter saying Americans feel "nasty" toward the "Washington Cartel." Cruz posted a link to the video of Janet Jackson's hit song "Nasty." "Donald seems to be a little rattled," Cruz told reporters before a town hall in Washington, New Hampshire on Monday. "For whatever reason he is very, very dismayed. I guess as conservatives continue to unite behind our campaign, as his poll numbers continue to go down, he's a little testier." Polls show Cruz and Trump locked in a tight race in Iowa, whose Feb. 1 caucuses lead off the state-by-state presidential nominating contests. But Trump is polling considerably better in New Hampshire. Cruz embarked on a five-day swing through New Hampshire this week as his numbers began to show new strength. Cruz questioned whether Trump is a true conservative, noting donations he's made to Democrats over the years, including $50,000 in 2010 to Chicago Mayor Rahm Emanuel, the former chief of staff to President Barack Obama. And Cruz rejected Trump's self-comparison to Ronald Reagan, saying he was "pretty sure" Reagan never supported or made large donations to Democrats. Trump, campaigning in New Hampshire late Monday, did not bring up his rival's accusations. In the past, Trump has said he made donations to Hillary Clinton for her Senate campaign and other Democrats not for ideological reasons but rather to serve his business interests. "The American people want a steady hand at the helm," Cruz told The Associated Press in an interview on his campaign bus Monday. "They don't want, I believe, a commander in chief who wakes up obsessed with the latest polls and driven to issue a frenzy of tweets. Instead, they want a principled, steady, conservative leader who will do everything necessary to protect this nation and keep America safe."