DES MOINES, Iowa (AP) — Republican Donald Trump is breaking from his reputation as a flame-throwing outsider with just days to go before Iowa's leadoff caucuses, highlighting his willingness to work with Democrats in Congress as part of a closing argument with a distinctly bipartisan tone. The billionaire businessman's promise to get things done in Washington is a direct contrast to leading GOP rival Ted Cruz, the Texas senator whose brief Washington career has been defined in part by his inability to get along with his own party. Trump's can-do message comes as adversaries begin pouring money into tough ads questioning his commitment to conservative values — attacks that some in the GOP's establishment wing have long awaited. In some ways, Trump's message plays into the hands of his Republican critics, who have long questioned his willingness to stick to conservative principles. Cruz allies have circulated no fewer than six anti-Trump ads in recent days, the bulk of the advertising coming from super political action committees in a billionaire-funded network called Keep the Promise. Katie Packer, a senior aide to Mitt Romney's 2012 campaign, launched a super PAC in recent days that's spending hundreds of thousands of dollars for an Iowa-focused anti-Trump campaign that includes television and radio ads in addition to mailers. [...] all the while, some high-profile conservatives are rallying behind Trump, who has thrilled many in the Republican base with aggressive plans to crack down on illegal immigration and ban Muslims from entering the country, at least temporarily, to safeguard against terrorist threats.