Republican presidential frontrunner Donald Trump is leading in the polls in the next key primary state.

A trio of recent surveys of likely GOP primary voters found Trump with a strong lead in Michigan, which awards its 59 delegates on Tuesday.

A new Monmouth University poll on Monday found Trump with 36% support to Sen. Ted Cruz's 23% support and Ohio Gov. John Kasich's 21% support.

A NBC/Wall Street Journal poll released Sunday found similar results: Trump garnered 41% support in that poll, compared to Cruz's 22% and Kasich's 13%. Local network Fox 2 also found Trump on even stronger footing, with a 22% lead over both Kasich and Cruz.

The surveys over the weekend also showed bad news for Sen. Marco Rubio, who appeared to be hovering around the 15% support threshold needed to pick up any delegates in Michigan.

Despite Trump's significant lead, Monmouth noted an encouraging sign for Cruz and Kasich.

While Monmouth found that survey calls made before Saturday and Sunday found Trump's support at 39%, calls conducted over the weekend showed a tighter race, with 32% of likely voters supporting Trump, while 26% broke for Kasich and 25% broke for Cruz.

This may not ultimately doom Trump. The former reality-television star has consistently performed best among voters who make up their minds early, while late-deciding voters tend to break for other candidates.

Trump has consistently performed best among voters who make up their minds early, while late-deciding voters tend to break for other candidates. Long the benefactor of a large, fractured presidential field, the real-estate magnate's Kentucky and Louisiana wins were much slimmer than predicted by some earlier surveys.